1) When holding Shift and clicking on a Guildhall, the upgrade window doesn't always open, even when the fifth level is already built. Through experimentation, I've concluded that the upgrade menu won't open if there are insufficient resources. This isn't very convenient because it's not entirely clear how many resources are actually needed. 2) If you open the upgrade window and close it without making any changes, you won't be able to open it again on the same day (it just takes you to the guild by holding Shift and clicking). Is this happening to everyone? If so, it seems like a bug, as I don't see any logic behind it. P.S. It would be helpful to add up-to-date information to the first post. I had to sift through half the thread to find the crucial message about needing to hold Shift to upgrade.