Try renaming your mods folder to _mods, this will disable it. And try launching again.
If you are able to launch the game with the mods folder disabled then you most likely need to update if you have not done so yet. This can be done by copying the update2.rpf from the update folder to mods/update.
If you can still not launch, with the mods folder named mods, after updating the mods folder then make sure you have a custom game config, heaplimit adjuster, and packfile limit adjuster installed.
If none of the above works then you will have to revert changes you've made to your mods folder until it works again or restart it entirely.