I had this problem as well which started for me last night. I spent hours trying to fix it until this morning, after going to sleep frustrated, I woke up and realized what I changed that started it for me.
I’m not saying this is going to be true for everyone’s situation but here is what I did that prevented it from happening when launching the game.
My Issue
- Launch the game from the bnet client
- Wait while the game would go through the loading screen process
- Warband would look like were going to visually start to appear
- Wow client would crash with a Memory Access Violation fault everytime
What fixed it
While testing various fixes, I discovered that if I stopped the login process by hitting Cancel when the client was starting and just simply waited a bit while letting the background music play (I tested and listening for the Drums to start seemed to be long enough for me), it would start perfectly fine every time when I logged in from the game while it was open.
I realized that I made a change last night when I decided to move my Paladin into my warband in the slot of where I previously had my Shaman. That simple change caused my problem because my Paladin was on a different realm, Illidan, than my other three characters which are on Zul’jin where my shaman is also located.
When testing after doing the wait strategy, I swapped the Paladin back out for the Shaman so all four characters in the main warband display were on the same server. After making that change, the problem has completely gone away and I’ve been able to continue to keep all my graphics options enabled (game is set to 10 right now even).
It’s almost like there is some sort of Memory faulting issue happening when loading the Warband character screen if you have characters from different servers in your warband. It was definitely causing my client to crash every time. I was even able to replicate the crash by swapping the Paladin back into the warband.
Not saying this is the fix for everyone or the OP but this is what worked for me that solved it.