Outlook 2016 hangs on updating folders
The command for the manual update procedure can be found here: Outlook will automatically download updates only unless the size of the changes is larger than 12.5% (one-eighth) of the total OAB size.
In that case the whole OAB is being downloaded again.
I'm a software engineer, so I can usually fix these issues pretty quickly, but this one has me beat.To answer the obvious, yes, I did shutdown and reboot (several times).Outlook is full of settings that are difficult and non-intuitive to locate.Renaming just a single or some of the files will result in an OAB corruption. A benefit of manually deleting the oab-file is that before they are being re-downloaded, you are working with the Online Address Book.
When you find things working correctly for you now but not anymore after the oab-file were redownloaded, you know that the issue is with the oab-files on the server and not on the client or the Address Book configuration in general.This means that in the worst possible scenario, an update to the Address Book won’t become available to the user until 48 hours after the change.This situation however is extremely rare since the default maintenance time on Exchange is at AM and updates and downloads are usually performed during working hours.Use Cached Exchange Mode but without OABTo always work with the Online Address Book, even when you have Cached Exchange Mode enabled, you can set the following Registry key and value.