# General

**URL:** https://discourse.nodered.org/c/general/7.md?page=57

[Latest](https://discourse.nodered.org/latest.md) · [Categories](https://discourse.nodered.org/categories.md) · [Tags](https://discourse.nodered.org/tags.md)

**Page:** 58

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## [Error: Invalid property expression: zero-length in ui-chart](https://discourse.nodered.org/t/error-invalid-property-expression-zero-length-in-ui-chart/94760)

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**Author:** [@nygma2004](https://discourse.nodered.org/u/nygma2004)\
**Replies:** 2\
**Last updated:** [23 January 2025 12:14 UTC](https://discourse.nodered.org/t/error-invalid-property-expression-zero-length-in-ui-chart/94760 "2025-01-23T12:14:53Z")

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I upgraded to the 1.22 version and my ui-chart which is configured to bar is giving me this error: Error: Invalid property expression: zero-length. I am passing an array with object with x and y properties: Has anyt…

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## ["Please add some UI nodes to your flow and redeploy."](https://discourse.nodered.org/t/please-add-some-ui-nodes-to-your-flow-and-redeploy/94832)

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**Author:** [@rhhollin](https://discourse.nodered.org/u/rhhollin)\
**Replies:** 3\
**Last updated:** [23 January 2025 08:54 UTC](https://discourse.nodered.org/t/please-add-some-ui-nodes-to-your-flow-and-redeploy/94832 "2025-01-23T08:54:26Z")

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I am running node-red on Windows 10, connected to an Arduino UNO running pyfirmata. I just completed updating all of the node-red related software, including the new dashboard 2. In my flow I use buttons and LED's. I h…

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## ["Serial Port Closed" when starting flow](https://discourse.nodered.org/t/serial-port-closed-when-starting-flow/94764)

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**Author:** [@rhhollin](https://discourse.nodered.org/u/rhhollin)\
**Replies:** 2\
**Last updated:** [22 January 2025 21:48 UTC](https://discourse.nodered.org/t/serial-port-closed-when-starting-flow/94764 "2025-01-22T21:48:57Z")

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I am running node-red v2.2.2 on a Windows 10 PC. The flow I am having issues with connects to an Arduino UNO via the node-red Arduino nodes. This particular flow worked OK for several months, but now is throwing an error…

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## [Tailscale webinar](https://discourse.nodered.org/t/tailscale-webinar/94829)

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**Author:** [@Paul-Reed](https://discourse.nodered.org/u/Paul-Reed)\
**Replies:** 0\
**Last updated:** [22 January 2025 16:58 UTC](https://discourse.nodered.org/t/tailscale-webinar/94829 "2025-01-22T16:58:32Z")

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Don't know how many users have followed @BartButenaers excellent blog about using Tailscale to increase the security of node-RED, but just seen that Tailscale are having a free webinar on 28th January, which may be of in…

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## [Homewizard P1 Meter - new\_user token API V2](https://discourse.nodered.org/t/homewizard-p1-meter-new-user-token-api-v2/94826)

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**Author:** [@Nice\_to\_have](https://discourse.nodered.org/u/Nice_to_have)\
**Replies:** 4\
**Last updated:** [22 January 2025 17:37 UTC](https://discourse.nodered.org/t/homewizard-p1-meter-new-user-token-api-v2/94826 "2025-01-22T17:37:08Z")

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Hi All, I recently got the Homewizard P1 Meter. Their documentation describes how to request a new user token, but i can not get it to work. I have my http post setup as: And this gives me: \[{"id":"a6d766c733…

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## [Node-red-node-annotate-image - using canvas](https://discourse.nodered.org/t/node-red-node-annotate-image-using-canvas/94653)

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**Author:** [@Sean-McG](https://discourse.nodered.org/u/Sean-McG)\
**Replies:** 5\
**Last updated:** [22 January 2025 14:34 UTC](https://discourse.nodered.org/t/node-red-node-annotate-image-using-canvas/94653 "2025-01-22T14:34:04Z")

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While playing with the Good-I-Deer nodes, I wanted to visualise the output, so I used the above node, however it is very slow (no offence @dceejay @knolleary ) :grinning: So with some help from chat-GPT I modified it to…

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## [Rule starts even if trigger doesnt change](https://discourse.nodered.org/t/rule-starts-even-if-trigger-doesnt-change/94801)

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**Author:** [@elBieneko](https://discourse.nodered.org/u/elBieneko)\
**Replies:** 7\
**Last updated:** [22 January 2025 14:29 UTC](https://discourse.nodered.org/t/rule-starts-even-if-trigger-doesnt-change/94801 "2025-01-22T14:29:45Z")

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Hello everyone, I'm very new to node red. I was running my smarthome on Openhab but now moving to Home Assistant. I was told to directly start creating rules with node red instead of the integrated rule engine. I have …

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## [How to install Node Red on Windows with the Windows Build Tools](https://discourse.nodered.org/t/how-to-install-node-red-on-windows-with-the-windows-build-tools/94816)

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**Author:** [@Technogeek](https://discourse.nodered.org/u/Technogeek)\
**Replies:** 0\
**Last updated:** [22 January 2025 08:56 UTC](https://discourse.nodered.org/t/how-to-install-node-red-on-windows-with-the-windows-build-tools/94816 "2025-01-22T08:56:45Z")

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I spent a couple of days trying to figure out what I need to install on Windows so that Nodes in Node Red that require the Windows Build Tools would install. I asked for help on this forum and got some great replies that…

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## [Connecting Arduino to Pi 5 and Node Red](https://discourse.nodered.org/t/connecting-arduino-to-pi-5-and-node-red/94746)

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**Author:** [@Technogeek](https://discourse.nodered.org/u/Technogeek)\
**Replies:** 7\
**Last updated:** [22 January 2025 01:12 UTC](https://discourse.nodered.org/t/connecting-arduino-to-pi-5-and-node-red/94746 "2025-01-22T01:12:04Z")

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I'm very new to the Pi and Node Red and I've run into a perplexing problem with Node Red and an Arduino with Firmata installed. I'm always able to see the USB port in Terminal as /dev/ttyUSB0/ however I'm absolutely unab…

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## [Substituting a variable in the JSON object used to for an http call](https://discourse.nodered.org/t/substituting-a-variable-in-the-json-object-used-to-for-an-http-call/94774)

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**Author:** [@invictagunner](https://discourse.nodered.org/u/invictagunner)\
**Replies:** 21\
**Last updated:** [22 January 2025 00:54 UTC](https://discourse.nodered.org/t/substituting-a-variable-in-the-json-object-used-to-for-an-http-call/94774 "2025-01-22T00:54:30Z")

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I am setting up the parameters for a http request node. For example, msg.payload={ 'client\_id': 'xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx', 'grant\_type': 'refresh\_token', 'refresh\_token': currentRefreshToken }; Fo…

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## [Limit a hexadecimal number to 8-bits](https://discourse.nodered.org/t/limit-a-hexadecimal-number-to-8-bits/94795)

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**Author:** [@redhead](https://discourse.nodered.org/u/redhead)\
**Replies:** 2\
**Last updated:** [21 January 2025 18:35 UTC](https://discourse.nodered.org/t/limit-a-hexadecimal-number-to-8-bits/94795 "2025-01-21T18:35:31Z")

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I'm working on a serial interface. The serial packet includes the checksum. The checksum is limited to 8-bits (two-digit hexadecimal number). Any 8-bit math overflows are ignored. For example, if the checksum is hexadec…

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## [Cronplus AGAIN: System Time Change Detected](https://discourse.nodered.org/t/cronplus-again-system-time-change-detected/94702)

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**Author:** [@malys](https://discourse.nodered.org/u/malys)\
**Replies:** 8\
**Last updated:** [21 January 2025 18:22 UTC](https://discourse.nodered.org/t/cronplus-again-system-time-change-detected/94702 "2025-01-21T18:22:44Z")

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Many times, my system is very slow on startup and logs are filled with this message: "System Time Change Detected - refreshing schedules! If the system time was not changed then this typically occurs due to blocking cod…

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## [New node always Function 1](https://discourse.nodered.org/t/new-node-always-function-1/94790)

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**Author:** [@Giamma](https://discourse.nodered.org/u/Giamma)\
**Replies:** 4\
**Last updated:** [21 January 2025 16:36 UTC](https://discourse.nodered.org/t/new-node-always-function-1/94790 "2025-01-21T16:36:17Z")

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Hi, I'm not sure but from the v 4.0.8 when I create a new node function the number displayed is always 1. It's just my problem?

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## [I need to perform an arithmetic operation between 2 variables of the same modbus device](https://discourse.nodered.org/t/i-need-to-perform-an-arithmetic-operation-between-2-variables-of-the-same-modbus-device/94258)

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**Author:** [@Monobeto93](https://discourse.nodered.org/u/Monobeto93)\
**Replies:** 4\
**Last updated:** [21 January 2025 15:33 UTC](https://discourse.nodered.org/t/i-need-to-perform-an-arithmetic-operation-between-2-variables-of-the-same-modbus-device/94258 "2025-01-21T15:33:38Z")

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I have converted MOT32 to float using a function, but when I take these two converted values ​​to another function to perform the arithmetic operation, there is a conflict between the payloads. I would really appreciate …

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## [Install erroring out GLIBCXX\_3.4.26 not found](https://discourse.nodered.org/t/install-erroring-out-glibcxx-3-4-26-not-found/94432)

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**Author:** [@KSum](https://discourse.nodered.org/u/KSum)\
**Replies:** 32\
**Last updated:** [21 January 2025 11:43 UTC](https://discourse.nodered.org/t/install-erroring-out-glibcxx-3-4-26-not-found/94432 "2025-01-21T11:43:40Z")

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I am trying to install the latest version of Node-Red using the Raspberry Pi instructions using the command: bash \<(curl -sL https://raw.githubusercontent.com/node-red/linux-installers/master/deb/update-nodejs-and-noder…

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## [Developing on Windows but running production flows on Raspberry PI](https://discourse.nodered.org/t/developing-on-windows-but-running-production-flows-on-raspberry-pi/94775)

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**Author:** [@invictagunner](https://discourse.nodered.org/u/invictagunner)\
**Replies:** 2\
**Last updated:** [21 January 2025 11:30 UTC](https://discourse.nodered.org/t/developing-on-windows-but-running-production-flows-on-raspberry-pi/94775 "2025-01-21T11:30:05Z")

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I have purchased a Raspberry Pi 5 starter kit and a fully developed production home automation running on Windows 10. The Raspberry Pi will only be used for running the production flows. I have no prior experience of R…

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## [TypeError: Object.hasOwn is not a function - Unable to import flow](https://discourse.nodered.org/t/typeerror-object-hasown-is-not-a-function-unable-to-import-flow/94772)

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**Author:** [@MLFR\_IOT](https://discourse.nodered.org/u/MLFR_IOT)\
**Replies:** 7\
**Last updated:** [21 January 2025 09:43 UTC](https://discourse.nodered.org/t/typeerror-object-hasown-is-not-a-function-unable-to-import-flow/94772 "2025-01-21T09:43:35Z")

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Hello everyone, I can't import any flow on node red right now : This is not working with external flows but also with the same flow I just exported from that node red device. Has anyone ever had this problem ? Doe…

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## [Template widget shows nothing](https://discourse.nodered.org/t/template-widget-shows-nothing/94758)

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**Author:** [@Le-Ze](https://discourse.nodered.org/u/Le-Ze)\
**Replies:** 2\
**Last updated:** [20 January 2025 22:49 UTC](https://discourse.nodered.org/t/template-widget-shows-nothing/94758 "2025-01-20T22:49:27Z")

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Hi. I have mqtt in node. The function will process the output. msg.payload = { temperature: msg.payload.temperature, humidity: msg.payload.humidity }; return msg; Exit function. {"temperature":18.3,"humidity…

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## [Weird HIVE MQTT happenings. (possible crying WOLF) But important to read!](https://discourse.nodered.org/t/weird-hive-mqtt-happenings-possible-crying-wolf-but-important-to-read/94761)

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**Author:** [@Trying\_to\_learn](https://discourse.nodered.org/u/Trying_to_learn)\
**Replies:** 4\
**Last updated:** [20 January 2025 22:23 UTC](https://discourse.nodered.org/t/weird-hive-mqtt-happenings-possible-crying-wolf-but-important-to-read/94761 "2025-01-20T22:23:16Z")

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Folks, this has started recently I believe and only today I've actually caught the problem. I use HIVE MQTT for a project that now can't be used anyway. :frowning: In saying that, I will raise my hand and say it was …

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## [Amend REST API port](https://discourse.nodered.org/t/amend-rest-api-port/94757)

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**Author:** [@ScheepersJohan](https://discourse.nodered.org/u/ScheepersJohan)\
**Replies:** 3\
**Last updated:** [20 January 2025 18:35 UTC](https://discourse.nodered.org/t/amend-rest-api-port/94757 "2025-01-20T18:35:30Z")

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Is it possible to change the port for a rest API?

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## [Flow with 10 MQTT "IN Node".. is better use just one "IN node" and split via "function node"?](https://discourse.nodered.org/t/flow-with-10-mqtt-in-node-is-better-use-just-one-in-node-and-split-via-function-node/94627)

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**Author:** [@lumanga](https://discourse.nodered.org/u/lumanga)\
**Replies:** 19\
**Last updated:** [20 January 2025 15:07 UTC](https://discourse.nodered.org/t/flow-with-10-mqtt-in-node-is-better-use-just-one-in-node-and-split-via-function-node/94627 "2025-01-20T15:07:17Z")

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Dear All, Hi, I have an old Raspberry Pi 3 running Raspbian Debian 11 Bullseye. I have installed Node-Red with the Mosquitto MQTT broker to receive signals from temperature/humidity sensors and current probes for home …

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## [Allen Bradley SLC-500 PLC and Node Red](https://discourse.nodered.org/t/allen-bradley-slc-500-plc-and-node-red/94725)

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**Author:** [@Surefire01](https://discourse.nodered.org/u/Surefire01)\
**Replies:** 6\
**Last updated:** [20 January 2025 15:02 UTC](https://discourse.nodered.org/t/allen-bradley-slc-500-plc-and-node-red/94725 "2025-01-20T15:02:07Z")

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Hi Folks. In a previous life I used Allen Bradley SLC-500's to teach electrical apprentices the basics of PLC's. These were programmed using RSLinx and RSLogix installed on a laptop and communicating through an RS232 c…

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## [Throttle mqtt traffic at flow startup](https://discourse.nodered.org/t/throttle-mqtt-traffic-at-flow-startup/94660)

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**Author:** [@mharsch](https://discourse.nodered.org/u/mharsch)\
**Replies:** 11\
**Last updated:** [20 January 2025 14:31 UTC](https://discourse.nodered.org/t/throttle-mqtt-traffic-at-flow-startup/94660 "2025-01-20T14:31:29Z")

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I have a MQTT host that charges for a specific rate of data points per minute. I'm able to stay below this rate for outbound traffic by pacing the inject nodes that trigger the flow. However, if I have many MQTT in nod…

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## [Solved Question on how to store api data to test function](https://discourse.nodered.org/t/solved-question-on-how-to-store-api-data-to-test-function/94755)

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**Author:** [@old-grumpy](https://discourse.nodered.org/u/old-grumpy)\
**Replies:** 4\
**Last updated:** [20 January 2025 14:06 UTC](https://discourse.nodered.org/t/solved-question-on-how-to-store-api-data-to-test-function/94755 "2025-01-20T14:06:46Z")

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I need to chance the function node code as my old service is now subscription. now going use " https://weerlive.nl/api/weerlive\_api\_v2.php?key=demo&locatie=Amsterdam" wget get that,no problem. I like to store this data s…

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## [Help in Function Node - Dynamic Table properties (CSV to HTML)](https://discourse.nodered.org/t/help-in-function-node-dynamic-table-properties-csv-to-html/94751)

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**Author:** [@smanjunath211](https://discourse.nodered.org/u/smanjunath211)\
**Replies:** 7\
**Last updated:** [20 January 2025 13:11 UTC](https://discourse.nodered.org/t/help-in-function-node-dynamic-table-properties-csv-to-html/94751 "2025-01-20T13:11:00Z")

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I have a simple flow, where i convert the contents of a CSV file into an HTML table for sending it as email body. for few rows in the table i need to colspan 6 columns so that they appear in a single cell based on the c…

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## [Any way to use plugins with nrlint?](https://discourse.nodered.org/t/any-way-to-use-plugins-with-nrlint/94743)

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**Author:** [@ThingsTinkerer](https://discourse.nodered.org/u/ThingsTinkerer)\
**Replies:** 1\
**Last updated:** [20 January 2025 11:42 UTC](https://discourse.nodered.org/t/any-way-to-use-plugins-with-nrlint/94743 "2025-01-20T11:42:53Z")

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Was trying to add an eslint rule but found it was deprecated and moved to a separate "stylistic" plugin. Tried adding this to nrlint, but to no effect. Anyone knows how to add it? Is it even possible? @stylistic/eslint-…

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## [How to Display a Vuetify Combobox Across All Pages but Load Data on Specific Pages?](https://discourse.nodered.org/t/how-to-display-a-vuetify-combobox-across-all-pages-but-load-data-on-specific-pages/94753)

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**Author:** [@Nandhini-Subramaniya](https://discourse.nodered.org/u/Nandhini-Subramaniya)\
**Replies:** 2\
**Last updated:** [20 January 2025 11:02 UTC](https://discourse.nodered.org/t/how-to-display-a-vuetify-combobox-across-all-pages-but-load-data-on-specific-pages/94753 "2025-01-20T11:02:37Z")

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Hi everyone, I'm working on a Vue.js project using Vuetify, and I have a v-combobox that I want to display on all pages in my application. However, I only want to load and render the data for the combobox on specific pa…

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## [Installation Error](https://discourse.nodered.org/t/installation-error/94723)

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**Author:** [@leftymuller](https://discourse.nodered.org/u/leftymuller)\
**Replies:** 23\
**Last updated:** [20 January 2025 10:12 UTC](https://discourse.nodered.org/t/installation-error/94723 "2025-01-20T10:12:34Z")

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Hello Good peoples, Just tried to install an instance of node-red on Debian 12 under proxmox I have done this a heap of times and never any problems However I get root@debian:/etc# node-red Illegal instruction (core…

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## [VEdirect victron node](https://discourse.nodered.org/t/vedirect-victron-node/94744)

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**Author:** [@pin32](https://discourse.nodered.org/u/pin32)\
**Replies:** 3\
**Last updated:** [19 January 2025 22:59 UTC](https://discourse.nodered.org/t/vedirect-victron-node/94744 "2025-01-19T22:59:15Z")

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Hello. I’m using this node to acquire data from a Victron smartshunt. I find a problem of which I cannot understand the nature, questioning him I obtain alternately in seemingly random way this information: \`{"PID":{"…

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## [Syntax errors when running the install script on raspberry pi](https://discourse.nodered.org/t/syntax-errors-when-running-the-install-script-on-raspberry-pi/94740)

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**Author:** [@bobs409](https://discourse.nodered.org/u/bobs409)\
**Replies:** 4\
**Last updated:** [19 January 2025 20:50 UTC](https://discourse.nodered.org/t/syntax-errors-when-running-the-install-script-on-raspberry-pi/94740 "2025-01-19T20:50:14Z")

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Trying to install Node red on my Raspberry pi 4 but it gives this error: /dev/fd/63: line 851: syntax error near unexpected token ;;' /dev/fd/63: line 851: ;;' This is the command I'm using: bash \<(curl -sL https://r…

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