I just ran a test myself and Ren'py seemed to build the new project just fine using the template with its current name! Are you using Windows or another OS? Happy to rename it if it is an issue, of course (thanks for bringing it to my attention)
Thanks for the reply! I'm on Windows 11 and using Ren'py 8.5.2. I also quickly checked it while running on Linux and the same exception occurs.
Alright! I'll alter it then just to be safe. Thanks for letting me know!