This morning i tried loading two different mod packs with Mekanism (Skyexchange and a private pack of my own) and both times got this line in the game output section of the launcher and loading just stopped

[06:10:57] [main/WARN] [FML/]: The coremod mekanism.common.launch.LoadingHook does not have a MCVersion annotation, it may cause issues with this version of Minecraft

No you have an NVidia video card? Did you recently update the drivers?
If you did, the new drivers broke something. You may need to re-install the older drivers.

The warning has nothing to do with the crashes, it's just a warning that some annotations are missing. That warning is already fixed in one of the development branches (1.10 branch).

The reason behind the crash could be, as @TehStoneMan said, be an up-to date NVidia driver.
https://www.reddit.com/r/feedthebeast/comments/5pydv9/dont_install_nvidia_gpu_driver_version_37849_it/

I followed up on the Nvidia driver issue and that solved the problem thanks.