Failed to open project. Check it is a valid Construct 3 single-file (.c3p) project. After updating.

Hello, i'm developing a game and when i updated construct to the latest version it gave me the error:

Failed to open project. Check it is a valid Construct 3 single-file (.c3p) project.

I don't know what to do or if i need to change the project file.

See Ashley's comment here:

github.com/Scirra/Construct-3-bugs/issues/6236

Just change your file type to .c3p. If you don't know how, go to file manager, click "view", find and click "show file types", and change the file type of your project to .c3p.