BUG in ALL releases of 2014 / backwards save compatibility?

[Megidolaon]

I'm playing Fate/Extra and the graphics were mostly fine until I tried a new build because someone suggested to get God Eater Burst to run (still crashes during character creation).

Turns out EVERY build in 2014 has a bug where in Fate/Extra the graphics are messed up (more than usual) in the dungeons.
In the top left corner are two smaller parts showing the whole screen yet again, one above the other.
together they cover at least a quarter of the screen.
Also the screen is constantly flickering.

That was not the case in v 0.96-190.
I made the mistake of saving in a new version and overwriting my old save state in 0.96-190.
Now I get an exception every time I try to load my new save state, is there a way to make it compatible for the old version?