Diagnosis
The field name of the decision operation you have used is not in theData Dictionary. This errors only occurs very seldomly. When you createdthe feature, the Data Dictionary contained the field name in thestructure valid for the feature. However, the structure was changed inthe meantime and the field no longer exists.

Procedure
Determine why the field name was deleted from the structure. Eitherinsert the field name in the structure or change the field name in thedecision operation.