In an attempt at troubleshooting that problem, I went into Battle.net settings and changed it to the Beta version and restarted it. Now it brings up the window frame, but cannot display any contents. Instead it displays a blank battle.net blue background, but no contents or controls, plus a Wine error dump dialog.
Is there any way to revert Battle.net back to the default non-beta version, without having to reinstall Diablo3 and Diablo4? Since I can’t access the Battle.net UI itself I’m not sure if this is possible.