Originally posted by: michaelfreimer

I'm solving a problem called Product_Mix with a quadratic objective function and linear constraints, but I'm getting the following strange error messages in the log file:

• Generating QCP model Product_Mix
• common_model.gms(2876104) 2933 Mb
• 2,864,606 rows 7,438,192 columns 14,647,600 non-zeroes
• 7,660 nl-code 589 nl-non-zeroes
• common_model.gms(2876104) 2928 Mb
• common_model.gms(2876104) 2928 Mb 1 Error
  • QCPfixer: could not spawn convert, rc = 1

• • • common_model.gms(2876104) 2928 Mb 2 Errors

• • • Msg=Operation not permitted

• • • common_model.gms(2876104) 2928 Mb 3 Errors

• • • Convert=gmscv_ux.out
    • SOLVE aborted

Any ideas?

Many thanks
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: michaelfreimer

Apologies, the editor made some formatting changes. Trying again:

Generating QCP model Product_Mix
common_model.gms(2876104) 2933 Mb
2,864,606 rows 7,438,192 columns 14,647,600 non-zeroes
7,660 nl-code 589 nl-non-zeroes
common_model.gms(2876104) 2928 Mb
common_model.gms(2876104) 2928 Mb 1 Error
QCPfixer: could not spawn convert, rc = 1
common_model.gms(2876104) 2928 Mb 2 Errors
Msg=Operation not permitted
common_model.gms(2876104) 2928 Mb 3 Errors
Convert=gmscv_ux.out
SOLVE aborted
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: SystemAdmin

It looks like you are not using CPLEX directly but using it through gams or something else?
In any case, this QCPFixer error message is not a CPLEX error message, so there must be something wrong with your wrapper.
This here is a very wild guess: CPLEX comes with a binary program called 'convert'. From the error message one may guess that your wrapper attempts to invoke that binary and does not find it.
Do you happen to work on Linux? If so then you could use strace to figure out what your wrapper is actually doing and if it indeed attempts to invoke the 'convert' program and that fails.
#CPLEXOptimizers
#DecisionOptimization

Originally posted by: michaelfreimer

Thanks,
Yes, you're right - I'm using CPLEX with GAMS. Knowing that the QCPFixer error message was not from CPLEX pointed me in the right direction. I'm still not exactly sure what the message means, but making some changes to the machine on which GAMS was running fixed the problem.
#CPLEXOptimizers
#DecisionOptimization