I ran into Error Code 800a0011 this morning when adding a list box control to a form in VBA. No matter what control I added, it gave this error:
could not complete the operation due to error 800a0011
Although annoying, there is a quick fix. Switch to the other VBA project that is loaded and ensure that you are not in debug mode. It seems I had an empty project (global 1) that had no code save for the "option explicit" option. I unloaded that project and the problem went away.