In Windows Explorer (File Explorer), with "File extensions" and "Hidden items" enabled under "View -> Show", in both "C:\Users\yourusername\AppData\Roaming" and "C:\Users\yourusrername\AppData\Local", right-click on the "Opera Software" folder, goto "Properties", switch to the "General" tab, click the read only checkbox to clear it (so that it's all white) and click apply. Then, switch to the "Security" tab, make sure your username is in the user list and make sure it has full control (all permissions set to "allow" except "Special permissions"), apply if necessary and OK out.

Then, in "C:\Users\yourusername\AppData\Roaming\Opera Software\Opera Stable\Default", delete the "History" file (and History Journal file if it's not 0 bytes). This will wipe out what history you have, but it's important to do to make sure Opera creates a fresh one that isn't corrupted.

Then see how things go.

If you still have issues and you're using Opera Sync, disable it for a while (or at least disable syncing of history) to test if that makes the issue go away.

Besides that, make sure you always shut down Opera yourself. Don't shut down or restart Windows while Opera is open even if other programs don't have an issue with that.

It might be good to make sure the time, date, time zone and daylight saving settings are correct on your computer and in Windows and remain correct so Opera doesn't think your history entries are old than 3 months for example.

It might be a good idea to back up the "History" file often.