What platform are you on? Just curious because that doesn't seem to be a common occurrence for most people? It'd piss me off too. I go from dashboard to a mission/stronghold no problem on Xbox.
Ps4 Pro. Its pretty typical for me since launch. I managed for most the game because I was enjoying the main story and character interactions, but now its become a strain because I'm trying to jump in a just enjoy the gameplay and getting loot.
On a good day it will boot up after two loops of being returned to the splash screen with errors. Once I get it in, a majority of the time I can play a mission or two before being kicked again. It typically happens at the end of the mission so I never get the loot until the next go around as far as I know. The last few times I've actually played I've been booted each time after the mission. I actually got off just now because I got kicked after a contract. I can't handle it anymore lol.
On a bad day, it can take up to 5 or 7 loops and errors at the main screen before I get in. Plus there's been several occasions now when I try to quickplay a mission or stronghold that I get booted, go back in and get the 95% load screen.
I say 15 minutes for getting in and 15 if booted because this was the worst case scenario and its happen to me a few times. Just the other day It took about 30 minutes to finally start playing. When your limited on time and you think to yourself, hey I can run a quick stronghold, and then your faced with that's, its sucks lol.
I think I've been pretty kind towards this game considering my experience. I like BW games and I enjoyed this one. But the issues that I'm having are making it extremely hard to enjoy post game.