# Error when opening dev tools
**URL:** https://discourse.nodered.org/t/error-when-opening-dev-tools/20394
**Category:** General
**Created:** [15 January 2020 16:46 UTC](https://discourse.nodered.org/t/error-when-opening-dev-tools/20394 "2020-01-15T16:46:59Z")
**Posts on this page:** 4
**Page:** 1
### Author:  [@echtelerp](https://discourse.nodered.org/u/echtelerp)
#### Post date: [15 January 2020 16:46 UTC](https://discourse.nodered.org/t/error-when-opening-dev-tools/20394/1 "2020-01-15T16:46:59Z")
Hi Node Red users,
I have a docker container with node red.
And every time I try to open my browsers developer tools, the container exits with the following error message:
* * *
## You should set your own key using the 'credentialSecret' option in your settings file. Node-RED will then re-encrypt your credentials file using your chosen key the next time you deploy a change.
15 Jan 15:41:26 - [info] Server now running at [http://127.0.0.1:1880/](http://127.0.0.1:1880/)
15 Jan 15:41:26 - [info] Starting flows
15 Jan 15:41:26 - [info] Started flows
15 Jan 15:41:52 - [red] Uncaught Exception:
15 Jan 15:41:52 - TypeError: Cannot read property 'warn' of undefined
at /usr/src/node-red/node\_modules/node-red-dashboard/nodes/ui\_base.js:93:29
at /usr/src/node-red/node\_modules/express/lib/response.js:434:22
at SendStream.onerror (/usr/src/node-red/node\_modules/express/lib/response.js:1044:5)
at SendStream.emit (events.js:198:13)
at SendStream.error (/usr/src/node-red/node\_modules/send/index.js:270:17)
at SendStream.onStatError (/usr/src/node-red/node\_modules/send/index.js:421:12)
at onstat (/usr/src/node-red/node\_modules/send/index.js:726:26)
at FSReqWrap.oncomplete (fs.js:153:21)
npm ERR! code ELIFECYCLE
npm ERR! errno 1
npm ERR! node-red-docker@1.0.0 start: `node $NODE_OPTIONS node_modules/node-red/red.js -v $FLOWS "--userDir" "/data"`
npm ERR! Exit status 1
npm ERR!
npm ERR! Failed at the node-red-docker@1.0.0 start script.
npm ERR! This is probably not a problem with npm. There is likely additional logging output above.
npm ERR! A complete log of this run can be found in:
npm ERR! /usr/src/node-red/.npm/\_logs/2020-01-15T15\_41\_52\_345Z-debug.log
anyone have an idea how to debug that?
---
### Author:  [@TotallyInformation](https://discourse.nodered.org/u/TotallyInformation)
#### Post date: [15 January 2020 16:52 UTC](https://discourse.nodered.org/t/error-when-opening-dev-tools/20394/2 "2020-01-15T16:52:35Z")
Can you share the versions of nodejs, node-red and dashboard that you are using?
---
### Author:  [@echtelerp](https://discourse.nodered.org/u/echtelerp)
#### Post date: [14 February 2020 18:30 UTC](https://discourse.nodered.org/t/error-when-opening-dev-tools/20394/3 "2020-02-14T18:30:49Z")
# Welcome to Node-RED
14 Feb 18:20:10 - [info] Node-RED version: v1.0.3
14 Feb 18:20:10 - [info] Node.js version: v10.16.2
14 Feb 18:20:10 - [info] Linux 4.19.76-linuxkit arm LE
14 Feb 18:20:12 - [info] Loading palette nodes
14 Feb 18:20:20 - [s7comm-Error] - Installation of Module net-keepalive failed because we might be on the wrong OS. OS=linux
14 Feb 18:20:20 - [s7comm-Info] - Debug configuration for logLevelNodeS7:{"debug":0,"silent":true}
14 Feb 18:20:20 - [s7comm-Info] - Debug configuration for logLevelNodeRED:{"debug":2,"silent":true}
14 Feb 18:20:25 - [info] Dashboard version 2.19.2 started at /ui
14 Feb 18:20:26 - [info] Settings file : /data/settings.js
14 Feb 18:20:26 - [info] Context store : 'default' [module=memory]
14 Feb 18:20:26 - [info] User directory : /data
14 Feb 18:20:26 - [warn] No active project : using default flows file
14 Feb 18:20:26 - [info] Flows file : /data/flows.json
14 Feb 18:20:26 - [warn]
* * *
Your flow credentials file is encrypted using a system-generated key.
If the system-generated key is lost for any reason, your credentials
file will not be recoverable, you will have to delete it and re-enter
your credentials.
## You should set your own key using the 'credentialSecret' option in your settings file. Node-RED will then re-encrypt your credentials file using your chosen key the next time you deploy a change.
14 Feb 18:20:26 - [info] Starting flows
14 Feb 18:20:26 - [info] Started flows
14 Feb 18:20:26 - [info] Server now running at [http://127.0.0.1:1880/](http://127.0.0.1:1880/)
---
### Author:  [@echtelerp](https://discourse.nodered.org/u/echtelerp)
#### Post date: [12 March 2020 20:33 UTC](https://discourse.nodered.org/t/error-when-opening-dev-tools/20394/4 "2020-03-12T20:33:57Z")
the problem seems to have gone with bumping the Node-Red version to 1.0.4, and node version 10, or maybe a restart. 🙂