So, is there any hard info on what exactly causes the problem? I've read that it's the login servers on patch days and I've read that validating files/deleting .exe/etc works, indicating a client issue. So which is it? Is it server side or client side?
You deleting files has nothing to do with it, it's human nature to think that correlation somehow implies causation when it doesn't. It's by sheer luck that login servers/download server/whatever they're using to authenticate files/users was able to reply to your request and allowed you to proceed.
It is the logon/patch server that is causing the issue, I say this because once you have validated the game files and all match up you are 100% on your end as far as the game goes. Now if you look at how the game loads ie launcher logs in and patches game if needed, then you can hit play to actually login. Getting stuck at 96% is my system waiting for the server to send my character data to me, without it it can't give me the character select screen. Once you get to the character screen and then can't login to a character (infinite login thing) is because same thing you are waiting for information from a server to be sent to you. Anyone that is deleting files and restarting is just wasting time, and time is just what is needed to fix the issue. The servers are overloaded with too many requests to handle. SOE should really look into how to reduce the bottleneck that is causing this issue as it will happen every patch as it has been until they fix it.
After the patch I'm stuck at %96 again. I did close the game and validated assets, but it's the same again. Edit: Restarted the PC, still at %96.
It's probably the login server taking it's usual post patch pounding. I'm impressed this thread keeps popping up with startling regularity. But if you are new here, you might want to start working on that master thesis you've been putting off for the past 8 years. This usually takes a few to several hours to clear up.
