Error Message when Changing Field Name

Error Message when Changing Field Name

I am trying to add a multi line field in my form.  It adds the field, but when I try and change the name, I get this error when it tries to save.  I tried modifying other forms and everything works fine, it just occurs on this form.  All other fields prior to this one saved fine.  I also tried to add different types of fields and got the same error for them.