Hi EvaFrisie -
Well the good news is that the Translucency Crash that you are getting is a result of a conflict with the Light Propagation Volume and has been fixed in 4.10. If you are using Source you can get the following commit:
https://github.com/EpicGames/UnrealEngine/commit/7df053eaa60394cc5eb6a4a395d4dd6d95493b88
For the 4.9.2 to 4.9.2 issue, can you check (or remember) if you are using GitHub source for one version and not the other also if you could open up the different versions and under Help >> About Unreal Engine and let me know what the CL # is listed as in each one. It should look something like this:
Thank You
Eric Ketchum