I know this is a super very uber old thread, but I was looking for the same issue. In my case I click "play" on the vba editor, it loads the form and Excel is blocked. There are no hidden/insensive operations running, form is just waiting for me to give an input on combobox, options, textbox, button.... but I can't use any excel. This is because the form is seen as a priority dialog window in front of excel, so it's impossible to use spreadsheet.

This is not a bug or something, it's a standard behavior bacause excel always runs form in a "modal" mode. What does "modal" mean? When a form is displayed in modal mode, it blocks all other Excel activities until it is closed. This happens because the application's focus is completely shifted to the form.

How to solve it? To unblock Excel and allow the user to work on other sheets while the form is open, you need to display the form in non-modal mode.

Here's how to do it: UserForm1.Show vbModeless