Are you looking to move a community from woltlab? We dont have an openly available converter at present, but its something we can discuss if its required
I would actually suggest if you have hundreds of notifications, you should probably adjust what you get notifications for. As you have pointed out there, having to sift through hundreds wastes time.
Check he isn't using a custom editor on his phone. We've not seen any other reports of this either. Unfortunately, this will be a device issue rather than one with your site.
Thank you for bringing this issue to our attention! I can confirm this should be further reviewed and I have logged an internal bug report for our development team to investigate and address as necessary, in a future maintenance release.
I would point out, the answer to this would generally be no. You would switch on notifications for these within your notification options. That way you will know as soon as there is a request
It looks like there is an issue with the videos application, looking at the error message there. I would suggest disabling that first of all. Other than that, I would need to see the issue while its in place.
If its showing that message, then the admin location at the very least is running PHP 7.3. As mentioned above, you will need to speak to your ohsting copany
Please go to System>Settings>Advanced configuration, and you will see a tab for them on there.
Check that, also check with all 3rd party items disabled. And check you are using a standard htaccess
It can be the case that some will abandon their developments unfortunately. The only real way around this is to have something developed specifically for yourself that you own and can have updated by anyone, should you wish to do so