Invalid parameter column definition

I have an assembly that contains a family table that can not be checked in. The following error message appears, "Invalid parameter column definition = pfb_augr__wldmt.asm, column (item) = TITLE2". NOTE: If TITLE2 is removed from the family table or if the contents is the same for all instances than the file can be checked in. In addition, all the other parameters work normally, including TITLE1 and TITLE3.

What is the problem and what is the solution to allow this file to be checked in?

Thank you,

WMP