Emulator

Game Name?
Mario Kart wii

Game ID?
RMCP01

What's the problem? Describe what went wrong in few words.
Crash when efb is to ram for the sun flare effect to work

What did you expect to happen instead?
not crash

What steps will reproduce the problem?
1.efb2ram
2.go on a track
3.crash after a while

Dolphin 3.5 and 3.5-367 are old versions of Dolphin that have
known issues and bugs, so don't report issues about them and test the
latest Dolphin version first.
Which versions of Dolphin did you test on?
4.0 and the latest dev built

Does using an older version of Dolphin solve your issue? If yes, which
versions of Dolphin used to work?
dont think so

What are your PC specifications? (including, but not limited to: Operating
System, CPU and GPU)
i7 4770k
660 ti

Are you using the 32 or the 64 bit version of Dolphin?
64

Is there any other relevant information? (e.g. logs, screenshots,
configuration files)
https://forums.dolphin-emu.org/Thread-custom-d3d-version-with-massive-performance-boost-and-a-lot-of-rendering-fixes

this guy has fixed the issue and has also given speed ups to the d3d option just by changing stuff in the exe and fixed many other bugs as well so maybe you can take some of his code and put it in hte official dolphin build which would make many people happy with the fixes it brings :)