Cannot GET /ui/loading.html

I wonder what is causing below error message in the Dev tools console for a Node-RED application that uses the dashboard. My environment:

Raspberry PI
Node-RED version: v1.0.6
Node.js version: v12.16.3
Dashboard version 2.22.1 started at /ui

Apparently, there is nothing broken in the application as it runs flawlessly.
Ok, I know.. if it is not broke don´t fix it... but at least wanted to understand what is going on. :wink:

When I try to access such endpoint from the browser I get the confirmation that the resource is not available:

Cannot GET /ui/loading.html

There is also a warning in dev tools console that I assume it is not related (but anyway I would prefer to understand the root cause and get rid of it).

Cannot GET /ui/js/angular-chart.min.js.map

I would be grateful if anyone could share any thoughts.

My first guess would be a buggy custom node. You could try searching from the Node-RED user dir if you'll find code referring to loading.html:

cd .node-red
grep -R "loading.html" *

If any file matches you can see from the directory name which node it is.


nothing to worry about
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It sounds odd for it to give an error like that? Maybe clearing the browser cache might help?

no, cleaning the browser cache does also not help. The only way to get rid of that message is by placing a loading.html in the dist folder or by changing the dashboard code

Ah, so it's a placeholder for an optional loading screen or?

yes, as in the link https://github.com/node-red/node-red-dashboard#loading-the-dashboard I posted

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Ah sorry. The preview image was a bit misleading. I assumed it was just a link to the repo home and didn't open it... Shame on me.

you are right, that preview image is indeed misleading. (I thought so when I saw the posted post, don't know how to get discord to not show these preview images :-))

About the other error, minimized javascript is hard to debug, since your dev tools will point you to a veeeery long single line js file, basically unreadable. For that so called source maps have been invented, which allow you to have the minimized code for the actual page but the unminified code for the debugger. Somehow that source map is not there, also nothing to worry about, as long as you don't want to debug angular-charts

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Thank you very much ! I can now deploy the application without fears.

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Not necessarily unless it's also obfuscated: https://developers.google.com/web/tools/chrome-devtools/javascript/reference#format

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cool, didn't know that :slight_smile:

Correct it's just a placeholder to load a loading screen from if you have a slow network / big dashboard / slow browser... A user requested that they wanted to customise one - so rather than build in a default one that we would overwrite on every upgrade it was simpler to just try to load it if it exists - and let it 404 if not, so the user could add whatever they want (or not).

Yep I understand. I guess it could be improved with a server side check but not like it's a big deal. Confusing at most what this thread shows.

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