My guess is the Project Template is corrupted, or when you created it, you left some old information in. You could take the newly created bad project, clean it up and fix it and save as a new Project Template with a different name. Now either delete or rename the faulty project with name to avoid for now.
From within Scrivener, click Help > Release Notes. This takes you to the latest version of Scrivener, which you can download and reinstall. Takes about 5 minutes for the whole process.
Exit Scrivener before reinstalling it.
If the problem was a corrupted template and it’s a Scrivener template, it will be replaced by the reinstalled package’s template.
If the problem persists, then it’s not the template that’s at fault.