The Attribute Assistant's expression method does not evaluate Null fields correctly.
Last Published: August 21, 2015ArcGIS for Desktop
Bug ID Number
January 30, 2015
May 20, 2022
ArcGIS for Desktop
Operating System Version
After review by the development team, it has been determined that this issue is related to a known limitation with the software that lies outside of Esri's control. The issue's Additional Information section may contain further explanation.
Use the correct Syntax. There cannot be a space between the between 'IsNull' and the '('.
The expression must not include a space between 'IsNull' and the '('.
The correct syntax should be:
IIF (IsNull ([Text1]