I am working in a Classic app and it seems the ability to use a background image for the sign-in screen is no longer working but it could just be something I am doing wrong. It is just showing a red sign-in screen as per the color theme I have chosen.
I just tested with one of my Classic Apps, with identical settings as yours, and it works as expected.
So I’m not sure what the issue might be with yours. Only thing I can think of is the image may have been deleted. If you try to load the image URL in a browser, does it work? What if you upload another image?
As a side note, you should consider migrating your App to the new version of Glide. Classic Apps are no longer supported. Whilst they might continue to work for the foreseeable future, I don’t know how long that can be guaranteed for. And they also don’t get any of the newer features or bug fixes.
Well lucky me, it took a couple of hours to update but its working now. Yeah, I would love to update but I can not afford the new prices which are way more expensive. My app is massive (almost 600 columns on the User sheet alone) and any upgrade would also be an unthinkable amount of work. I am going to try and make do until it can no longer run.
