Well, this is what I was told:
" A HTTP 404 error is a client side error that means that the origin web server couldn’t find a requested file. Cloudflare does not generate 404s, so this would indicate something is not configured correctly with your hosting provider. It’s possible that a document root with your origin is pointed to the wrong host name or different working directory. The best next steps would be to work with your hosting provider to identify what potential misconfiguration could be in place that would cause the origin to look for a file where it doesn’t exist."
"The response about the 404 is not helpful, unfortunately. What I’m trying to explain is as follows:
An app shows as installed via the “Your Installed Apps” tab. When I click on “Edit Install” for that particular app, I get the HTTP 404 error. Most of the sites I have at most 3 apps: Particles, Corner Banner and Add HTML. I’ve used others (Cursor Sparkles and SharPay.io), but the first 3 I listed are the main ones.
Maybe the answer to the following question will be the best help of all: Is the Particles App still available to be installed (at all) via Cloudflare apps? If so, then perhaps there is an issue with my hosting provider’s configuration, as the last response I received from Cloudflare support suggested.
Thanks in advance for your help!
[PS] - I forgot to mention that I am able to uninstall the other apps listed (Corner Banner, Add HTML, Cursor Sparkles and SharPay.io) with no problem, and they also show up as available apps when I search for them, whether I have them installed or not."