"Internal Error: Sub-system: MLS, File: /quartus/synth/mls/mls_netlist.cpp" Error

[Altera_Forum]

Hello,  

 Whenever I try to compile a design that I am currently working on, I always receive this error message:  "Internal Error: Sub-system: MLS, File: /quartus/synth/mls/mls_netlist.cpp, Line: 2016 cloned_sgate != 0 Stack Trace:  0x8bd44: MLS_ROOT::delete_mls_netlist + 0xb3e4   0xafee0: MLS_ROOT::clone_mls_netlist + 0x23840   0xb062f: MLS_ROOT::clone_mls_netlist + 0x23f8f   0x553db: MLS_INTERFACE::MLS_INTERFACE + 0x1762b   0x3a1c2: MLS_INTERFACE::get_ready + 0x4472   0x336d5: MLS_INTERFACE::~MLS_INTERFACE + 0x17345   0x3519a: MLS_INTERFACE::call_named_function + 0x82a   0x34f38: MLS_INTERFACE::call_named_function + 0x5c8   0x3c659: MLS_ROOT::start_from_mls_netlist + 0x49   0x613ef: scl_start + 0x5ba8f   0x656c3: scl_start + 0x5fd63   0x2e374: scl_start + 0x28a14   0x2ef1d: scl_start + 0x295bd   0x2f47f: scl_start + 0x29b1f   0x5475: scl_run_parallel_mls_script + 0xfd5           0x128ed: qexe_get_command_line + 0x206d   0x1573e: qexe_process_cmdline_arguments + 0x59e   0x15851: qexe_standard_main + 0xa1     0xa7f8: msg_exe_fini + 0x58   0xaf3c: msg_exe_fini + 0x79c   0x1f14: MEM_SEGMENT_INTERNAL::~MEM_SEGMENT_INTERNAL + 0x194   0xb8bf: msg_exe_main + 0x8f     0x159bc: BaseThreadInitThunk + 0xc   0x2a2e0: RtlUserThreadStart + 0x20    End-trace   Quartus II 64-Bit Version 13.1.0 Build 162 10/23/2013 SJ Web Edition"  From the message above, I believe that this is a netlist error, however I am not sure what is specifically causing a netlist error. Has anyone ever encountered this message? Thank you.