You could check the "sopc_bulider_log.txt" file and see what it says.
I don't know what the codes are. However, I will submit one possible cause for this that perhaps might be useful.
1 - SoPC builder expects there to be an associated Quartus project with your SoPC system.
2 - SoPC builder tries to run a TCL script for the associated Quartus project at the end of its system generation.
3 - If it cannot find the associated project for whatever reason, the entire system will generate completely correctly. However, SoPC builder will throw an error because the TCL script failed to run properly.
This is normal for me. I launch SoPC builder as a megawizard not associated with a Quartus project so even when I generate my SoPC system from the GUI, I get this error. It's no big deal and I ignore it. It seems feasible to me that the same would occur when running SoPC builder from the command line.
Here is what the error looks like:
Info: Command: quartus_sh -t trio_sopc_setup_quartus.tcl
Error: Evaluation of Tcl script trio_sopc_setup_quartus.tcl unsuccessful
Error: Quartus II Shell was unsuccessful. 1 error, 0 warnings
Error: Peak virtual memory: 45 megabytes
Error: Processing ended: Tue Jan 20 09:21:10 2009
Error: Elapsed time: 00:00:00
Error: Total CPU time (on all processors): 00:00:00
------------------------------------------------
ERROR: Project does not exist or has illegal name characters: C:/Projects/trio/fpga/X2/trio_top/src/sopc/. Specify a legal project name.
while executing
"project_open -current_revision "C:/Projects/trio/fpga/X2/trio_top/src/sopc/""
(file "trio_sopc_setup_quartus.tcl" line 2)
------------------------------------------------
# 2009.01.20 09:21:11 (*) Completed generation for system: trio_sopc.
# 2009.01.20 09:21:11 (*) THE FOLLOWING SYSTEM ITEMS HAVE BEEN GENERATED:
SOPC Builder database : C:/Projects/trio/fpga/X2/trio_top/src/sopc/trio_sopc.ptf
System HDL Model : C:/Projects/trio/fpga/X2/trio_top/src/sopc/trio_sopc.v
System Generation Script : C:/Projects/trio/fpga/X2/trio_top/src/sopc/trio_sopc_generation_script
# 2009.01.20 09:21:11 (*) SUCCESS: SYSTEM GENERATION COMPLETED.
Warning: System generation was successful, though errors were reported.
I pulled the above text from the "sopc_builder_log.txt" file.
Jake