Opening projects in Wappler 3 and 4

I had opened a couple of projects in the last couple of beta versions, just to have a look at the new UI etc. I’ve just discovered that doing this has meant the projects have disappeared from Wappler 3. If I reopen them in Wappler 3, could there be any problems - eg does Wappler 4 change any project-related files etc? These are not projects I’m working on and I made copies of files to test, but it would be helpful to know if it’s possible to revert back to v3.