MATLAB: Make error: Making simulation target is not recognized as an internal or external command, operable program or batch file.

matlab2012bmatlab2013asimulinksimulink coder

Making simulation target "viterbi_with_punct_obj_rev01_sfun", …
'viterbi_with_punct_obj_rev01_sfun.bat' is not recognized as an internal or external command, operable program or batch file.
I've configured a model in Matlab 2013a,saved the configuration to file, and imported it to a project done in Matlab 2012b, is this the reason for the error? The new configuration was such that I can generate code while there is a variant subsystem in the model.
Furthermore,Can I work on a Matlab 2013a project and run it on Matlab 2012b?
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