How to bring back tools panel?

[RJNixy]

I can still open tool panels from the Window menu, the problem is when I start Illustrator every time, all the workspace presets are not available, I can only choose my customised one, but it doesn't bring any tool panels. The Reset, New workspace, Manage workspaces options are all grey.

[Dan Rodney]

Have you tried resetting your preferences? https://helpx.adobe.com/illustrator/using/setting-preferences.html

Sometimes bugs are caused by preferences gone bad.