Hey Norm
Did as instructed and the exact same thing is happening.
I don’t know if this helps, but my TimeMachine was not working with Mojave so Apple had me erase and install Mojave again in something I think she called Upper and Lower Case installation? I don’t remember exactly what she said. All my other apps still work after the reinstallation but Blocs.
Thanks again for the continued support.
Bill
Ah that’s it, Blocs doesn’t support a case-sensitive file systems. I’m amazed you were instructed to use case-sensitive as it’s not the default setting for MacOS.
Unfortunately Blocs will not work on this setup, I’m hoping to add support but it’s months away. The only way to get it to work is to switch to none case sensitive. I’m very sorry for the inconvenience, let me know how you would like to progress and if you require a refund for the time being.
No refund. I’m really happy with Blocs. I’m not a programmer, web designer - just a regular guy who can use the app my own way.
I’m going to reinstall based on information from the apple website and going to install * APFS: Uses the APFS format, recommended for volumes using macOS 10.13 or later.
Thanks
Bill
Erased my MacBook Pro down to Mavericks and reinstalled everything.
Blocs Works Perfectly.
Thank you for the help Norm.
No, thank you. Reinstalling your OS is a huge ask to get the app running.
So thank you and Merry Christmas 
It’s a great app Norm. You should be very proud of your accomplishments.