After more reading of this thread. I see I am having the exact same issue! All my files were freshly downloaded from the latest link and only from the 2.1.6 directory of the zip file. The SPIFFS files were included butI do see that it is commented out. So I renamed those files, but it makes no difference. Same error.
So you have two different people who experienced the same issue from this code. I don’t see a relationship to the spiffs files.
So what did we miss?
I am curious to know what pbecchi did differently that allowed him to verify his code.