I thought they were connected on both ends
Here is a vague but temporary solution for those who really don't mind having item frames removed from the game until there is a proper bug fix.
This is going to remove Item Frames from your 14w18a jar file, so if you'd rather not remove ItemFrames from this version (even though it crashes minecraft if you place them) then do not proceed and wait for Mojang to release fix, or modify the code yourself.
If you do not mind removing ItemFrames from the game to be able to play on 14w18a on a map that does render the ItemFrame entity;
Simply replace the current snapshot version (14w18a) in /versions/ in the minecraft folder with 14w18a-custom
This custom version does not contain cce.class, which is needed to render the ItemFrame entity.
PS: Don't worry, this does not remove any ItemFrames in your Minecraft Map, but instead it will simply not render them.
Remember that this does not resolve the issue, but is useful incase you want to play on your Map and are experiencing this issue
I think this bug fix can be abandoned.