After reading various reports of problems, we would like to give you some tips to work around problems with the patch versus moded games.
The patch changes a lot of things "under the hood" in physics code, but the result is that some properties (variables) were changed or removed. Any physics mods out there may now have values stored in them which can crash the game. If you are using a physics mod, switch this mod off, it can be done individually per-profile and per-mod - you just need to go to Profile Edit screen. Really, for any mod user, the Profile Edit screen is now important for you.
If you acted hastily and decided to nuke all mods just to make sure the game doesn't crash because of mods, you may in fact hurt yourself. As described above, for the time being switching off any physics mods is a good idea (until you obtain fixed mods from their authors). On the other hand, many cargo mods people are using have become embedded into their save game files, and their removal can be a source of a different type of crash. So you need to be selective about which mods you remove and which you don't - it may be the case that both removing none and removing all mods may be wrong, and you need to find the right mix.
It's not just physics and cargo mods, there are also problems related to sound mods, as the updated game has changed some stuff and added retarder sounds, if you sound mod is "masking out" our new sounds by an old sound bank, the game may crash when it cannot find expected sound effect.
If you are a Steam user using mods, the situation may be even more complicated - with mods embedded into save games and the game automatically updating to version 1.3, players may have been caught by surprise. The above suggestions should help, but in case you want to revert to previous version of the game on Steam, it is now possible, we have made the older version temporarily available through Steam, see for more info here:
http://steamcommunity.com/app/227300/discussions/0/864959088248519109/.