Before I explain about the problem I must say that I had the problem since around November so not related to the patch, and it is not a save file but just loading plain gm_contruct.
So when I load the map I will just get stuck on loading resources and I have to close the game via task manager to exit. I can play multiplayer fine and I can play on my own server just fine. It only happens in singleplayer. I have removed my addons and re-tried but no dice.
By the way, my server is run from the same computer I play on and I did not have it up when I attempted to load.
I also left it loading for about 8 hours and it still made no progress.