Why am I unable to start my MATLAB Engine application when I have two versions of MATLAB installed?

I have two versions of MATLAB installed and have linked my Engine application against one of them. However, when I try to start it, it fails.

Answer 1

[MathWorks Support Team]

This enhancement has been incorporated in Release 2008a (R2008a). For previous product releases, read below for any possible workarounds:

If your application fails when using MATLAB Engine, there are two things that you should check:

1. Be sure that the MATLAB version you linked against is first in your system PATH environment variable.

2. Open a DOS command prompt and then change your working directory to MATLABROOT/bin/win32 using the CD command, where MATLABROOT represents the directory in which MATLAB is installed on your system. After that, issue the command ".\matlab /regserver" and then close the MATLAB window that appears. This registers that version of MATLAB as a COM automation server. This is required for proper Engine startup.

Alternatively (for #2), run the following command from MATLAB and then close both MATLAB's:

   eval(['!', '"', fullfile(matlabroot,'bin','win32','matlab.exe'), '"',' /regserver &'])