I'm building an app with lots of pages. When I tried to open it again this morning, everything was clickable; I could click the buttons in the middle (UI Canvas, Launch, Theme, etc.) until I tried to navigate to other pages by clicking the 'Home Page' in the left corner. Now, I can't edit other pages and can't click any of the buttons in the middle either.

I tried to refresh the page and clicked 'Data' and then clicked 'Home Page', but all it shows me is that the pages are empty.

I was able to launch the app on web preview and it works normally, but I just can't edit other pages now. Duplicating the project and trying to navigate to other pages in the duplicated project results in the same error.
Any suggestions?