Tried to serve up '/config/www/github/custom-cards/button-card.js.map' but it does not exist

[johntdyer]

Checklist

• I updated the card to the latest version available
• I cleared the cache of my browser

Describe the bug
I have tried this in Safari and Firefox and I get this error in the logs

2019-05-13 08:38:41 ERROR (MainThread) [custom_components.custom_updater] Tried to serve up '/config/www/github/custom-cards/button-card.js.map' but it does not exist

In Firefox console logs I get the following;

Source map error: SyntaxError: JSON.parse: unexpected end of data at line 1 column 1 of the JSON data
Resource URL: https://automation.xxxx/customcards/github/custom-cards/button-card.js?track=true
Source Map URL: button-card.js.map[Learn More]

Version of the card
Version: 1.8.0
Home Assistant: 0.92.2

To Reproduce
This is the configuration I used:

Screenshots
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Expected behavior
A clear and concise description of what you expected to happen.

Desktop (please complete the following information):

• Browser Firefox 66.0.5 (64-bit) and Safari Version 12.1 (14607.1.40.1.4)

Additional context
Add any other context about the problem here.

[RomRider]

You can safely ignore this error. This map file is a file that gets automatically generated for debugging purpose, I'm going to see if I can release the file without the reference to it.

And by the way, the type is module not js in the resources.

[johntdyer]

`And by the way, the type is module not js in the resources.``

@RomRider - Where did I say it was js vs module ?

[RomRider]

I was wondering about the strange issue in FF, that's why ;)