MacOS High Sierra , cannot open application because it may be damaged or incomplete

[Institutional]

So I was downloading Xbox 360 controller drivers and then it asked me to restart my mac, then i when i log in my computer functions as normal but some applications show this message: 'can not open application because it may be damaged or incomplete', my first instinct was to restart my computer but it only made it worse happening to ALL my finder applications and files. Please Help my mac is unusable at this point!!!!





I tried A. 'fake reinstalling macos' (without deleting files)

B. First Aid w/ disk utility

C. Apple support



I don't want to reinstall mac os entirely so if anyone can help it would be greatly appreciated.

 

[iMac-Do-You?]

Had to say without seeing it firsthand, however it sounds like the OS hard drive *may* be having issues. I've had a faulty hard drive (SSD) that didn't show anything up on First Aid in disk utility.
First port of call would be to restore from last time machine backup PRIOR to the issue (you DO have a backup, don't you!?).
If that doesn't work - backup important files / programs / emails etc to an external usb drive, and do a full reinstall formatting the hard drive - yes I know you don't want to to, but if your Mac is unusable, it may be the only option.
If thee are still problems after that, you know that the problem is hardware (likely the hard drive).

P.S. If you have not been keeping backups of your system and files, now is the time to start considering doing so, external USB drives are relatively cheap now and Time Machine is easy to set up.