This has happened several times. I'm working on a Solution that uses some dll, like OpenTK or EmguCV.
I've added the UI components to my designer toolbar (or they appear automatically under "Custom components" after adding the references).
I work on my project for a while, and at some point I can't go to design editor anymore. It complains that it can't find the referenced dll.
this has forced me to start over several times, but now I'm stuck.
I create a new Solution, add the referenced dlls, I can't drag and drop the UI components to the form designer. If I look into "Configure sidebar", it says that it can't find the dlls.