Hi Carl,
There have been lots of changes since version 2.3.9.3. You should deploy all the files not just the dlls.
Also I do not recommend modifying the mojoPortal source code, any custom code should be in your own projects, forking the mojoPortal source code is a bad idea.
For what you are doing you should instead implement and plugin a custom user registered event handler. This can be done with no modifications to mojoPortal soruce code.
Best,
Joe