We are on Laserfiche 9.2.1 and we had a query with addresses where the last field is the UNIT, (it may have a value or be blank).
With this query:
{[Property]:[Street Number]="1888", [Street Quadrant]="SW", [Street Name]="8", [Street Type]="ST", [Unit]=("")}
The result was this error
But everything was fine with the following query where everything is the same but the UNIT field with the empty value is the first field sought:
{[Property]:[Unit]=(""), [Street Number]="1888", [Street Quadrant]="SW", [Street Name]="8", [Street Type]="ST"}