Huge thanks to Brian K who set us on the right path to resolution.
com.ptc.pfc.Implementation.pfcExceptions$XToolkitNotFound solved, we have an environment variable that is supposed to point to the .jar files on the client machine. On one computer, the files were located within the pro/e installation files. When we moved them out, the toolkitnotfound went away. I am not sure why this fixed it. Probably a pointer to the literal path and not the environment variable.
Error in the method initProESession() : com.ptc.pfc.Implementation.pfcExceptions$XToolkitCommError. We had multiple connections to pro/e sessions without disconnecting. Eventually, we would exceed the number we are allowed. Erik