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Optimization Solver:Common error codes

Last Updated:Apr 01, 2026

The MindOpt solver returns negative integer error codes when a runtime error occurs. This page lists all error codes, their causes, and how to fix them.

Error codes in the -10 range may carry a secondary error code from the authentication license system. If you see error -10, check the Authentication license error codes section to identify the root cause.

Solver runtime error codes

Error codeDescriptionSolution
-1Unspecified internal error.Check whether this is a secondary error code — see the Authentication license error codes section. If this is a primary error, contact us.
-2Out of memory.Increase available memory or reduce the scale of the optimization problem.
-3Invalid parameter.Check the input parameters.
-10Invalid license.Check whether the license is set correctly. For secondary error codes, see the Authentication license error codes section. For license configuration steps, see 4. Configure authentication files. If you use solver version 0.20.0 or later to solve Mixed-Integer Linear Programming (MILP) problems, apply for the required permissions by email. See Download V0.20.0 for details.
-11The MINDOPT_HOME environment variable was not found.Set the environment variable as described in 3. Check environment variables and perform a test run.
-12Failed to load the MindOpt dynamic library.Check the dynamic library. If the problem persists, reinstall the software package.
-1000I/O communication error.Check the file input and output.
-1001Failed to read data from the file.Check whether the file to be read is correct.
-1002Failed to write data to the file.Check whether the data to be written is correct and whether you have write permissions.
-1003Path error.Check whether the path exists and whether you have write permissions.
-1100File parsing error.Check whether the file to be parsed is correct.
-1200Invalid token ID for the remote computing service.Check whether the token ID is valid and entered correctly.
-1201Failed to connect to the remote computing server.Check whether the server address is correct and the network connection is stable.
-2000Error inputting or reading the optimization model.Check whether the optimization model is valid.
-2001The optimization model is empty.Check whether the optimization model was provided correctly.
-2002Invalid row index for the model.Check whether the referenced row index is within the valid range.
-2003Invalid column index for the model.Check whether the referenced column index is within the valid range.
-2004Invalid row name for the model.Check whether the referenced row name is correct.
-2005Invalid column name for the model.Check whether the referenced column name is correct.
-2006Invalid index for the symmetric matrix.Check the input data.
-2007Invalid row index for the symmetric matrix.Check the input data.
-2008Invalid column index for the symmetric matrix.Check the input data.
-2010Unrecognized string attribute.Check whether the model's string attribute API is used correctly.
-2011Unrecognized integer attribute.Check whether the model's integer attribute API is used correctly.
-2012Unrecognized real number attribute.Check whether the model's real number attribute API is used correctly.
-2013Unrecognized real number attribute for the symmetric matrix.Check the input data.
-3000The solution is unavailable.Check whether the solution to the optimization problem was generated correctly.
-3001The primal ray is unavailable.Check whether the primal ray was generated correctly.
-3002Solver statistics are unavailable.Contact us.
-3003Unrecognized basis status value.Check whether the basis status value is set correctly.
-3004The Irreducible Inconsistent Subsystem (IIS) is unavailable for this model.Check whether the problem type is supported.
-3005The IIS is inactive for the solvable model.No IIS exists for a feasible model.
-4000Error setting a parameter.Check whether the parameter setting API is used correctly.
-4001Error getting a parameter.Check whether the parameter retrieval API is used correctly.
-9000The maximum number of iterations was reached.Check the maximum iteration limit setting.
-9001The maximum solving time was reached.Check the maximum solving time setting.
-9002The solving process was interrupted by Ctrl+C.Check whether the process was interrupted by a Ctrl+C command.
-9003The node limit was reached.Check the node limit setting.
-9004The consecutive node limit was exceeded without finding a better solution.Check the problem model. If the issue persists, contact us.
-9011The selected optimization algorithm is not supported.Check the solving method settings and the license scope. Check whether a newer version supports this algorithm, or contact us.
-9012The solver does not support the input problem type.Check whether the input file is valid. Check whether a newer version supports this problem type, or contact us.
-10000 to -19999Numerical error in the simplex method.Contact us.
-20000 to -29999Numerical error in the interior-point method.Contact us.
-30000Numerical error while computing the IIS.Contact us.

Authentication license error codes (secondary error codes for solver error code -10)

These errors relate to the fl_client.ini authentication file configuration or network connectivity. For configuration steps, see 3. Use an Alibaba Cloud license key for authentication.

Error codeDescriptionSolution
-1Request timed out.Check your internet connection. If the network is stable, increase the timeout period in the configuration file (default: 2 seconds). See 3. Use an Alibaba Cloud license key for authentication.
-2Failed to create a socket.Check the network connection.
-3Failed to set the socket to non-blocking mode.Check the network connection.
-4Failed to parse the host.Check the network connection and verify that server.name is correctly configured in the configuration file. See 3. Use an Alibaba Cloud license key for authentication.
-5Connection failed.Check the network connection.
-6Write request failed.Check the network connection.
-7Read request failed.Check the network connection.
-200Configuration file error.Check the fl_client.ini configuration file. See 3. Use an Alibaba Cloud license key for authentication.
-201URL error.Verify that server.name is correctly configured in the configuration file. See 3. Use an Alibaba Cloud license key for authentication.
500Internal server-side exception.If you use solver version 0.20.0 or later to solve MILP problems, apply for the required permissions by email. See Download V0.20.0. If the issue persists, contact us.
400Invalid request format.Check that the fl_client.ini file is complete, that ak_id and ak_secret are correct and valid, and that no placeholder content remains unmodified. See 3. Use an Alibaba Cloud license key for authentication. If the issue persists, download and reinstall the software package, then contact us if the problem remains.
401Unauthorized — the LicenseKey failed verification.Check that the LicenseKey belongs to the Alibaba Cloud account that corresponds to the AccessKey. View your LicenseKey in the console > Purchased Services.
410The resource has expired.The LicenseKey has expired. Go to console > Overview to renew it.
409Insufficient concurrency.The number of concurrent tasks has reached the limit for the purchased LicenseKey. To increase the limit, go to console > Overview to change the configuration. Note that completed tasks must be released promptly. For long-running tasks, you can set MaxTime to limit the total time consumed and release concurrent resources right away. If a solver program terminates abnormally (such as a crash), concurrency is not released automatically — release it manually from the console or wait for the connection to time out.
403No permission.Check whether the Alibaba Cloud account has granted the required permissions to the RAM user. In the account's authorization settings, search for "opt" to find the relevant permissions.

Console SDK runtime error codes

For authentication error codes returned by the Alibaba Cloud console SDK, see the Error Center.Error Center

404: Check whether the AccessKey ID and AccessKey secret are correct and use a matching AccessKey pair.