Crash in Quartus II 10.0

[Altera_Forum]

I am experiencing a crash every time I try to compile my code.  

 Back trace: Internal Error: Sub-system: OPT, File: /quartus/synth/opt/opt_op_mux.cpp, Line: 1394 cdb_is_connected(iterm)  Stack Trace:  0x10c5c2: RTL_OPERATOR::mux_has_uniform_data + 0xe2 (SYNTH_OPT)  0x1137a8: RTL_OPERATOR::minimize_and_merge_mostly_muxes + 0x228 (SYNTH_OPT)  0x113f09: RTL_OPERATOR::family_aware_crack_muxes + 0x99 (SYNTH_OPT)  0x47d2e: RTL_OPERATOR::exit_process_muxes + 0xae (SYNTH_OPT)  0x47f84: RTL_OPERATOR::exit_cleaning + 0x124 (SYNTH_OPT)  0x15c70d: RTL_SCRIPT::call_common_rtl_fns + 0x4fd (SYNTH_OPT)  0x15e46f: RTL_SCRIPT::call_named_function + 0x41f (SYNTH_OPT)  0x15a57e: RTL_SCRIPT::process_script + 0x4ee (SYNTH_OPT)  0x2aa5: opt_process_netlist_scripted + 0x645 (SYNTH_OPT)  0x33a7: RTL_ROOT::process_sgate_netlist + 0x4c7 (SYNTH_OPT)  0xeee93: SGN_SYNTHESIS::high_level_synthesis + 0x153 (synth_sgn)  0xeffb5: SGN_SYNTHESIS::process_current_stage + 0x265 (synth_sgn)  0x7c924: SGN_EXTRACTOR::synthesize_partition + 0x104 (synth_sgn)  0x7e8c0: SGN_EXTRACTOR::synthesis + 0x150 (synth_sgn)  0x7efc3: SGN_EXTRACTOR::synthesis_and_post_processing + 0x83 (synth_sgn)  0xc561: sgn_qic_full + 0x1e1 (synth_sgn)  0x321c: qsyn_execute_sgn + 0xac (quartus_map)  0x1981b: QSYN_FRAMEWORK::execute_core + 0x8b (quartus_map)  0x1c271: QSYN_FRAMEWORK::execute + 0xc1 (quartus_map)  0xd9f1: qexe_get_tcl_sub_option + 0x981 (comp_qexe)  0x10326: qexe_process_cmdline_arguments + 0x416 (comp_qexe)  0x10424: qexe_standard_main + 0x84 (comp_qexe)  0x1753e: qsyn_main + 0x5e (quartus_map)  0x1c91: msg_main_thread + 0x11 (CCL_MSG)  0x1a08: _thr_final_wrapper + 0x8 (ccl_thr)  0x1c05: msg_thread_wrapper + 0x85 (CCL_MSG)  0x8db6: mem_thread_wrapper + 0x34 (ccl_mem)  0x2e373: msg_exe_main + 0x63 (CCL_MSG)  0x1892c: _main + 0x1c (quartus_map)  0x1ee39: __alloca_probe + 0x189 (quartus_map)  0x16fe6: RegisterWaitForInputIdle + 0x48 (kernel32)  End-trace    Any suggestions about what I should do?

[Altera_Forum]

Contact Altera MySupport and give them these messages with your project.

[Altera_Forum]

Internal errors are issues that Altera didn't code for, so there's not a nice clean message and they're almost impossible to debug. As MSchmitt said, file it with Altera. The other options are the more generic types of debug: 

- Make sure you have the latest version of Quartus - Try to remember what changes you made that introduced the IE to see if it can be narrowed down to a specific "change", and then see if that is a valid change or if it can be done another way. - Try to reduce your design to sub-components and see if they have the problem. (Searching in the dark) - Randomly change synthesis stuff to see if that helps. Change the Optimization goal between Balanced/Area/Speed. Turn off/on Physical Synthesis. Add a Partition. That's completely guessing in the dark, but might work while you wait for a resolution.