Script error when evaluating old field value

Script error when evaluating old field value

Becoming frustrated with ZOHO Support

Found that you can't apply an IF or SET statement against any old values (any old code still works)

For example if you create a new form say ZOHO TEST and create a single line field called TEST

In the Workflow Script, On Edit Validate if you create an IF statement to look at the old content of the field TEST this error occurs

Error at line number : 1 
Variable 'old' is already defined of datatype '1013228000006314713' but trying to update 'zoho_test' datatype

Anyone else experiencing similar issues?