I found a solution, but not the problem.
How I fixed it:
I just created a template for each form, created a new project, and imported everything into the new project. One thing that I found useful is in the new project is to add an existing item (CTRL + D
), and group select (maybe, don't know if you can) and select all the non-code/form/designer/etc. files (like text files or images) and then import them.