Integrity check errors:
The Opus install has been corrupted by something. Could be malware, antirivurs, or a failing system drive.
Try reinstalling Opus:
- (Use Settings > Backup & Restore in Opus to backup your config, if desired.)
- Uninstall Opus via the usual Settings > Apps in Windows.
- Reboot.
- Reinstall Opus.
- (Restore the config backup via the same menu that made it, if desired.)
If the problem still happens, check the files are not being corrupted:
If the files are being corrupted, something is seriously wrong at a deeper level in the system, outside of Opus.
"Windows cannot access the specified device":
If Windows is unable to open a text file, and showing that error, it suggests either a problem with the drive itself or some software is blocking the file from being read. This could be antivirus going wrong, or it could be malware.
"Program Error Encountered":
I would not worry about this error until the others are resolved, as it is likely a symptom of the deeper problems which are causing the other errors.
If the other errors are fixed and it still happens, we can investigate it in detail.