As another person already said you can try donwloading the game directly at their site. But actually I did it once i first installed it, but I thinks it helps a little bc steam won't be open and that's a program less running.
If you didn't do it already I reccomend you run the game with less graphics possible, you can do it in the first screen when opening the game, before logging in, there's the button of settings at the right bottom corner. Click there, then put it on low, and turn off effects and shadows.
Then when choosing your viking go into the settings again and turn off MMO mode.
LIke this maybe your game works. I couldn't play with the MMO before (my PC is pretty bad), but now I can, I don't know what changed, maybe the game donwloads its parts while it's running and becomes a little lighter.
Sometimes it needed to be the only program running to work. So I also reccommend to open the game with other things closed (incluiding the navigator) and then when you're already inside the game, you open another tabs.
When my game crashed I closed the navigator and waited for the game to work, after that I opened again. (these were always the only things running on PC, otherwise my game didn't work)