Join Session and Create Session not working in 4.13?

I’ve recently managed to make my project work in 4.13 preview after updating from 4.10. (Thanks to Doug for the help!) After doing so, I worked up some function errors from the update, including Overlapping functions new delegate parameters thanks to Rama’s guide - 4.12 Transition Guide - C++ - Unreal Engine Forums . So after this I’m getting errors from the Create/JoinSessions functions that were previously working on 4.10… as reference for how I set up both functions, I used the following tutorial, so I’ve made them exactly how it’s made in here (being called initially by blueprint callable events as stated at the end of the tutorial). A new, community-hosted Unreal Engine Wiki - Announcements - Unreal Engine Forums

Thanks to eXi for a wonderfull guide. This being explained… Create session isn’t providing really an error, but now it always return the boolean bWasSuccessful as false without having made any updates into the code. not generating or allowing the 2nd delegate : OnStartSessionCompleteDelegateHandle to be called.

As far as Join Session… Visual studios is now providing a warning stating :

*Warning C4264 'bool UGameInstance::JoinSession(ULocalPlayer ,int32)’: no override available for virtual member function from base ‘UGameInstance’; function is hidden

Any feedback as always is more than welcome!!