you can open personal bank but guild cannot be seen apparently you can deposit into the guild bank but that is all. I found if you disable bagnon guild feature bagnon will work the way it's supposed to.

The checkbox to enable/disable bagnon's guild bank frame is grayed out for me :(

Edit: Ah, it is a separate addon, so it can be disabled in the main addon list.

+1 Same issue, Personal bank and bags are all good now, but Guild Bank throws a LUA exception.

If you'd like the exception detail let me know, I can get it for you later today.

I just turned the guild bank piece of Bagnon back on after today's update, and the guild bank appears to be functioning correctly.