Not sure if this helps, but in order to test my 13.3 MSP issue, CA had me install the 14.2 connector and I got a compile error too, with MSP 2010. I got it to work with MSP 2013, . CA said that 14.2 is supported with MSP 2010 sP2 and 2013 SP1.
Is yours on 2010?
The 14.2 has a new choice about installing the legacy driver or it defaults to the Microsoft Project Interface. (i.e. new driver).. do you know if that was changed or did you accept the default?
Do you have OWB installed as well or just MSP? Often if you have both, you will need to update OWB too.
One thing I noted was that the install prompted me to reboot but the install was not done. I had to say no to reboot and then the Add in completed. When I did an uninstall, it kept say the program was in use, so I had to let it process -- it was all very odd, but again, though I was testing on 13.3 for a specific issue, the install itself seemed off. Once I actually let it finish and then reboot, my compile error was gone
Do a full uninstall including remove the modules from MSP organizer, remove the PPM setup folder, check the registry files, etc.. Ensure Java 7.. reboot after an uninstall and try again?