Post-fit simulation of NCO MegaCore

I have a simple test project with a MegaCore NCO. I can do functional simulation using the .vho file, but the netlist generator refuses to create an .sdo file:

Error: Can't generate netlist output files because the file "C:/Altera/90/DrJohn/NCOtest/incremental_db/compiled_partitions/NCOtest.root_partition.map.atm" is an OpenCore Plus time-limited file

Does this mean that it is impossible to do post-fit simulation with MegaCore functions? Or is it because I don't have the correct license?

Thanks, John