I created a user control with 32 buttons and loaded 16 into my main form. I couldn't get the buttons to visualize how I wanted them so changed them to panels. However I forgot to remove the controls from the main form first and ended up having to edit the designer text as it wouldn't display.
Subsequently when I had fixed all the errors the controls were not displaying correctly and when I removed them and tried to re-load them they had disappeared from the toolbox and I can't get them back. My other projects also don't have any of my user controls in the toolbox although they work ok.
A new project won't display user controls so something must have got disabled but I can't find where.
Using Studio Community 2019 on Win10 - I have done a repair und upgrade to 16.9.2. Net vs 4.8.04084