What does "No registered plug-in" exception mean for MEX calls?

I have an MEX function that works fine when I call it from MATLAB (R2013b), but when I try calling it from (R2014b), I get the following exception, which shows up at the MATLAB command prompt:

Unexpected Standard exception from MEX file: What()is: No registered plug-in.

Is anyone familiar with this exception or have insight into what the fix is for it?

I inserted mexPrintf() statements in my MEX C++ code and noticed that the exception occurs when it reaches the first call to an API function from another package that the MEX function calls. (See figure below.)

Again, this works just fine with MATLAB 2013b (and with MATLAB2012), even on different Windows machines. However,it gives the exception with 2014b. I did re-build the MEX function (Visual Studio 2010 Professional 10.0.30319.1 RTMRel) with the configuration manager settings set to include the correct MATLAB 2014b paths--just as we do for 2013 and 2012. I double checked config. manager settings and rebuilt multiple times in different directories--for both the 2013b runs and the 2014b runs. The PC is a Dell Precision T5600 (64 bit) with Windows 7 Professional. The MATLAB install is 64bit.

Any recommendations would be appreciated.

[James Tursa]

Do you use the mex command from within R2014b to do the building, or are you building using some project file within MSVS?

[Will]

I use MSVS to build the project. I use an MSVS solutions file to open the project into MSVS. Then I build it from the MSVS "Build/Build Solution" menu.