I really need help on this because I lost my hopes to correct the problem.
I am using Office Communications Server 64bit libraries. There are 3 dlls I use in the pro
This is an old question, but was still the top result when I had this same issue today. I had switched my project compilation in Visual Studio to target x64 instead of 'All CPUs' (it's on a 64-bit machine). As per the other answers, there would be two ways to fix it - either change everything to 32-bit or everything to 64-bit. In this case, I needed 64-bit.
KabanaSoft's answer worked perfectly for me. Still correct as of Visual Studio 15.6.6.