debug.log also generated after automatic update check in opera task scheduler, there's no solution to stop this, you can delete task scheduler, but sometimes debug.log reapear in opera folder with same message, new chromium + maybe webview also causes this logs to reapear, it started around few months ago, i found this logs in many folders, but main folder is operagx, sometimes desktop+utorrent folder, or documents, so this is common problem probably, it always says same thing in the log:
Check failed: false. NOTREACHED log messages are omitted in official builds. Sorry! probably it is fixable
