When I run the Extension: update process for SecurityCheck Pro I get an almost immediate response of "Sorry I can't satisfy your request" on my screen. This also is the response on launching the basic site too.
Haven't had tome to explore the origin of the 'Sorry' message issue - is it database? The site seen via FTP seems intact. DB is 5.5.30, PHP is 7.3.17
Anyway it's definitely the SecurityCheck Pro update that's causing the problem at during the same session I've successfully done other updates. Luckily I had recent Akeeba backups and now I'm up to date except being stuck at Securitycheck Pro 3.1.11.
Do you mean you get the "can't satisfy..." message when do you try to update Securitycheck Pro???
That message doesn't belong to my extension. Do you have any other security product installed? Did you try the update from Joomla or did you try to update it uploading 3.1.12 version file?
Sorry for all the questions but I need to understand what's exactly your problem.