DWSIM 4.2 (Update 3)
When I drag&drop a "CAPE-OPEN Unit Operation" from the "Custom Blocks" frame into the flowsheet, the "Add CAPE-OPEN Unit Operation" dialog pops up, giving the options to
1) select a detected CO-UO and press OK or
2) press Cancel
Problem:
When I press Cancel, a unit is nevertheless added to the flowsheet. Trying to delete this unit from the flowsheet raises an unhandled error/exception: "Object reference not set to an instance of an object." The current flowsheet becomes useless.
I hope this behaviour can be fixed.