Modpack version
1.64d

Can the issue be reproduced?
Unknown

Logs
Rendering screen crash.txt

Issue
I was playing along, and tried to do a JEI Search using the '|' (Shift+) symbol. When I typed that, my game switched between Full-Screen and windowed mode. I tried several times, and then went into settings/controls to try to determine what was causing it and to disable the offender. On typing that key into the search bar, my game froze and crashed. On trying to boot back into the game it crashes with a rendering screen/out of index error. I did have optifine on while playing, but the crash is continuing even after i removed optifine.

Deleting your options.txt file should fix this :)

And that worked?

Other then apparently losing my /resources folder, (#1254) which I have had happen to about 3/4 of my installs of this pack...