CRC compiler-error message

[Altera_Forum]

Hi, guys, 

 I am following the "CRC compiler user guide" to see the CRC generator and checker simulation.   I got the following error message when I was trying to compile and simulate the crcdemo.v  error: can't generate netlist output files because the file "d:/fyp_extra/crc_project/testbench/new_project_testbench/incremental_db/compiled_partitions/crcdemo.root_partition.map.atm" is an opencore plus time-limited file error: can't generate netlist output files because the file "d:/fyp_extra/crc_project/testbench/new_project_testbench/incremental_db/compiled_partitions/crcdemo.root_partition.map.atm" is an opencore plus time-limited file error: can't generate netlist output files because the file "d:/fyp_extra/crc_project/testbench/new_project_testbench/incremental_db/compiled_partitions/crcdemo.root_partition.map.atm" is an opencore plus time-limited file error: can't generate netlist output files because the file "d:/fyp_extra/crc_project/testbench/new_project_testbench/incremental_db/compiled_partitions/crcdemo.root_partition.map.atm" is an opencore plus time-limited file   It seems like the OpenCore plus feature expires? I don't quite get it.  Thanks in advance