Just jumping in here and am having the same problem. I have a
subscription to Adobe CC and have always used Acrobat Pro to add my
signature to a document along with the date. In this case, I've
downloaded a W9 form from the IRS and have successfully added my
previously saved signature but can't 'fill in' the date next to my
signature. I have really enjoyed filling out PDF's previously using
Acrobat Pro in lieu of printing and then all of a sudden I'm receive the
same error message as documented ...