Yes, I read the post quite carefully. In your first post, you wrote:
giving the clear impression that the error appeared after moving the files, with no further action on your part. In your second post, you wrote:
That was a key difference that let me find both the source of your problem and a temporary solution. Something in the program has changed since the developer wrote the Guide. It may affect all operating systems, or it may only affect macOS.
To successfully change your application data folder location, follow the instructions in the Guide. However, after (1) moving all files from your old application data folder to the new one and (2) changing the data path preference—at which point you will see the InvalidOperationException error, click OK and close the program. When you relaunch the program, the application data path will be changed to the new folder.
I will write a bug report to bring this to the developer’s attention.