Internal Error: Sub-system: WSC, File: /quartus/neto/wsc/wsc_port_data.cpp, Line: 293

Due to a problem in the Quartus® II software versions 10.0 and later, this error message may be generated while running the EDA Netlist Writer if the option to maintain hierarchy in the output gate-level simulation netlist has been enabled.

To avoid this error, turn off the option by performing the following steps:

1. Open the Settings dialog box by selecting Settings... on the Assignments menu
2. Display the Simulation settings page by selecting Simulation under EDA Tool Settings
3. Open the More EDA Netlist Writer Settings dialog box by clicking the More EDA Netlist Writer Settings... button
4. Select the option Maintain hierarchy and change the setting to Off

This problem is scheduled to be fixed in a future version of the Quartus II software.