I have to write a validation rule on the standard object 'TASK' . If the picklist value of the 'Subject' field is 'Status Update' then the 'Description' field should not have any value. I am trying to write the rule but always I am getting the below error.
Error: Incorrect parameter type for function 'ISPICKVAL()'. Expected Picklist, received Text
Below is my Validation Rule.
AND(ISPICKVAL( Subject , "Status Update") , NOT( Description = NULL ) )
Please help me in knowing where I am going wrong.