I discovered the source of my error. When I deleted the txt9 control (textbox) I neglected to change the count of a For loop from 9 to 8 so a function call was being made on an non-existent object.

As I am new to programming, I am learning the hard way that the error message generated, in this case "Form Object not Found" is often not really the problem at all. It is an error message that was passed "downstream" by another error.