SolverSDK: Problem could not be saved. SolverSDK: Problem could not be saved. Not supported variable type.
LpWrite cannot be used with «QP» objects defined using QpDefine or «Nlp» objects defined using NlpDefine. It can only be used on linear programs defined using LpDefine. A likely cause of this error is trying to call LpWrite on a QP or NLP.
It is also possible that LpWrite was unable to write to the indicated file location. If you are sure you are passing an LP, then check the filename and ensure that the destination location is valid, and that you have permissions to write to that location.
The Not supported variable type message occurs when you try to save an NP containing integer types that are not supported by the file format, such as grouped-integer variables. Our experiments indicate that this variation only displays for the "LPFML" format, and not for the "LP" or "MPS" formats, even though grouped-integer types are not supported in any of these formats.
Correct the possible errors mentioned above and try saving the file again.