请问哪位大神能帮忙解决一下internal error BPM 的错误

cherry1

我在网上看了有类似于这种的错误，让删掉db文件夹，但是试过了没有用  
封装之后出现了这种问题，但是源代码没有
Internal Error: Sub-system: BPM, File: /quartus/db/bpm/bpm_boundary_port_hide.cpp, Line: 438
gnd_lcell == NULL
Stack Trace:
    0x3980f: BPM_BOUNDARY_PORT_HIDE::process_gnd_ports + 0x24f (db_bpm)
    0x3c3e7: BPM_BOUNDARY_PORT_HIDE::post_hide_operations + 0x7 (db_bpm)
    0x1293d: BPM_BOUNDARY_PORT_MANAGER_IMPL::hide_boundary_ports + 0x44d (db_bpm)
    0x58c8a: AMERGE_MERGER_OP::perform_post_merge_operations + 0x47a (atm_amerge)
     0x32bb: amerge_combine_netlist + 0x2db (atm_amerge)
     0x34d2: _amerge_mini_merge + 0x12 (atm_amerge)
    0x143e8: QSYN_FRAMEWORK::do_mini_merge + 0x268 (quartus_map)
    0x1a964: QSYN_FRAMEWORK::write_qic_databases + 0x8d4 (quartus_map)
    0x1cd69: QSYN_FRAMEWORK::write_databases + 0x49 (quartus_map)
     0xf2d3: qexe_get_command_line + 0x1523 (comp_qexe)
    0x116b7: qexe_process_cmdline_arguments + 0x387 (comp_qexe)
    0x117a4: qexe_standard_main + 0x84 (comp_qexe)
    0x17ede: qsyn_main + 0x5e (quartus_map)
     0x1b91: msg_main_thread + 0x11 (CCL_MSG)
     0x1be8: _thr_final_wrapper + 0x8 (ccl_thr)
     0x1b05: msg_thread_wrapper + 0x85 (CCL_MSG)
     0x218a: mem_thread_wrapper + 0x4a (ccl_mem)
    0x28a03: msg_exe_main + 0x63 (CCL_MSG)
    0x1938c: _main + 0x1c (quartus_map)
    0x24ab4: __ftol2 + 0x1ce (quartus_map)
    0x18493: BaseThreadInitThunk + 0x23 (KERNEL32)
    0x641c7: RtlAreBitsSet + 0x87 (ntdll)
    0x64197: RtlAreBitsSet + 0x57 (ntdll)

End-trace

Quartus II Version 11.0 Build 157 04/27/2011 SJ Full Version