Most of the time I am getting these massive animations or char.xsip patches. Usually between 200 and 900mb. It takes a really long time.
Even if only one of the accounts gets this patch, when the other try and log in, they crash. Sometimes, they do get into the game, but with the other account still patching animation or char.xsip, all my animations and actions are broken on those chars, until the patching completes. Then when the patching completes, the animations get "unstuck" on the online accounts, and the offline one is finally able to log in.
This has been happening multiple times daily this past few week.
I'm not the only person with multiple accounts experiencing this issue.
for now make sure one character is completely loaded into the game world before you try to log another one in. - this seems to keep the patcher from doing those updates. (before when I would log multiple characters in at the same time I had that same problem)