Improved error handling needed when downloads folder not configured correctly.

[dyfrig]

I restored a backup to my local XAMMP server. The site was working and I could access the backend however when I tried to download a jdownloads file I had a HTTP error 500. I turned on debug system and had the following error :
Error  ClassNotFoundError
HTTP 500 Whoops, looks like something went wrong.
Attempted to load class "CategoriesHelper" from namespace "JDownloads\Component\JDownloads\Administrator\Helper".
Did you forget a "use" statement for another namespace?

I first thought this was to do with different setups on the server but then realised this was to do with the downloads folder setting requiring an absolute path and so was incorrect on the local server.  It would be better if the software handled this and gave a meaningful error.

[ColinM]

Hi
The error reporting you see here is from Joomla so jD does not get to look at it.

I have added a section in the Xampp documentation about this problem.
https://www.jdownloads.net/documentation/general-items-v3-9/creating-a-joomla-test-site-on-xampp#preparation-for-jdownloads
Will maybe add elsewhere
Colin