New bolting 'unable to evaluate' error

I've got a DTSE that references the BDIA on the flange and Nozzle as per the following expression

( BDIA OF BLTP 1 OF BLRF NUM 1 OF CATR  )

Data type NULL, default 0

The property area of the form is populated with a definition of NULL and a No. set to a parameter value not on the SCOM

I've got a DTSE that references the BDIA on the flange and Nozzle as per the following expression

( BDIA OF BLTP 1 OF BLRF NUM 1 OF CATR  )

Data type NULL, default 0

The property area of the form is populated with a definition of NULL and a No. set to a parameter value not on the SCOM