masked_madman

This issue you are having here is a hard one to solve. This is because it is a unique situation where two mod issues with gui conflict and prevent the game from launching. To fix this issue you will have to manually weed out the erroneous mods. Remove all mods from the mods folder and put them on your desktop. Divide your mods into manageable subgroups of 5-7. Put the first group into the mods folder and run Minecraft. If you get the same error (same crashlog report with gui missing), then you have managed to locate at least one of the two problematic mods. You can weed it out from there. Try to avoid other silly errors, such as not pairing up libraries with their respective mods, when making and testing groups. If there is no error, create a new folder in the mods folder called MODS GROUP 1 [SAFE] and put them in the folder. (Minecraft will still be able to run these mods, do not worry). Then do the same for the next group. Should you still have a problem, reply to this message. The reason that mod authors can't really prevent this error is because it requires two mods, usually ones far apart from each other, to combine and create this error.