I wrote a workflow which included a customized activity written with C#. When I click "Additional Criteria" button in Pick addtional criteria dialog as I wanted to modify trigger criteria, an error occured, said
Unable to render the criteria. '<Criteria xmlns=http://Microsoft.EnterpriseManagement.Core.Criteria/> <Expression> <UnaryExpression> <ValueExpression> <Property>$Context/Property[Type='384eebc6-0a62-9a9e-ddb4-09d1618d3d83']/b3cfd8c2-8e9a-fad8-49e3-d480bf3daab6$</Property> </ValueExpression> <Operator>isNotNull</Operator> </UnaryExpression> </Expression> </Criteria>' is not valid.
What is wrong with it? Thanks!