10.13.3 High Sierra does not have an "Anywhere" option in Security Preferences for allowing apps. The only applicable option is "App Store and identified developers" This means that every time I try to open KRITA 4 I have to allow it to reject the app, then open again and go to Security and press the "open anyway" button. Every. single. time. Including when I'm in the middle of something and Krita crashes. Furthermore, Krita 4 does not seem to save work with a recovered file after crashes, or am I missing something?

I've gone back to using the older version, because I'm in the middle of a job, and I can't afford to lose work or spend time reconfiguring.
Any help on these issues would be greatly appreciated!!

This still works on my mac with the latest macOS:

https://support.apple.com/kb/PH25088?locale=en_US

I'm not sure about the problems with autosave files: those work for me.

wow youre lucky , at least youre able to do that , i cant even open it at all in my high sierra , it wont let me and thats sad because the mac is the best computer one can get

Check System Preferences > Security & Privacy and allow it to run, or try control-click. The web is full of suggestions on how to make it work, and I must have tried one of them that worked...