The document has been changed since it was created and use of extended features is no longer avail

Getting this error when opening some old forms from last year.  Tried the recommended solutions (remove address book file) but still happening.  The reader is 64-bit, and the forms were made in 32 bit adobe, could that be the issue? Also, getting an error reading file (109) if I use Save a copy.  Not getting that if I just save the file directly.

Also, the acrobat pro that created the files can still open them and update them, no problem.