Current Status: Resolved
The instant app generator is currently malfunctioning for users with Windows PCs. I'm sorry for the errors, I know this is not what you paid for. We're aware of the issue and we're working hard on it now. The underlying cause of the error requires a lot of reconfiguration on the backend to fix so it will take a few days. We expect to have the issue resolved by April 30th, but we will update here if that date changes for better or for worse.
As a temporary workaround you can access the generator using a Mac computer or a mobile device, or you can use the Photoshop templates if you already have Photoshop installed on your computer. Again, I know this is not what you paid for and I sincerely apologize. If you'd like to get in touch please email firstname.lastname@example.org.