Type NULL into type OleStr

lotuselans4

hello,

i am new here and on FastReport. I am not a program specialist and i use fastreport as reporting software in a specific software. I tried to use the same layout including pascal code that works in a software where fastreport is 4.1.17 in a new evolution of the same software where fastreport is 4.13.1
But in presence of codes as
if (Pos('BnF',<frUserDataset.wpname>)>0) then AR.Visible := true else AR.visible := false;

it doesn't work on the new evolution of the software. i receive the following error messag:
The following error(s) have occurred: Could not convert variant of type (Null) into type (OleStr). Unknown variable or datafield: fruserdataset.wpname

Anyone able to help me? thank you.

Umberto Ferrari
italy

gpi

Try

if (Pos('BnF',<frUserDataset."wpname">)>0) then AR.Visible := true else AR.visible := false;