Quartus II v8.1--Internal Error: Sub-system: BPM,

internal error: sub-system: bpm, file: /quartus/db/bpm/bpm_boundary_port_hide.cpp, line: 1336

!bp_iterm->is_inverted()

stack trace:

end-trace

quartus ii version 8.1 build 163 10/28/2008 sj full version

This is the error information reported by QuartusII v8.1 when I use it to compiling a PCI Express project within a SignalTap file, but the compilation will be successful if I remome the SignalTap file from this project. The SignalTap file is needed. How can I resolve this problem?Thank you!