Hi René;
FYI ... (for both PB Classic and PB.Net):
PB Version .Net Version Supported
======== =================
PB 12.x 3.5
PB 12.5.x 4.0
PB 12.6.x 4.5
Note1: Now saying that, a lower migrated PB version application will still have the old .Net assignments in it. So for example a PB 12.x built application migrated to PB 12.6 will have .Net 3.5 assembly references.
Note2: While PB 12.6.x is .Net 4.5 complaint, I am not sure how v4.5 aware it really is.
Regards ...Chris