Import Server Configuration fails:
Preparing existing management agent configuration for update completed.
Import attribute flow rules compare starting…
Import attribute flow rules have been changed.
Metaverse configuration validation starting…
Metaverse configuration validation successfully completed.
Preparing existing metaverse configuration for update starting…
An error was encountered while trying to update the metaverse configurations.
Exception from HRESULT: 0x80230920
Error encountered trying to prepare the existing metaverse configuration.
Server configuration import FAILED.
Oh great, and you’ve also unselected all the connector space attributes in every MA for me, thanks very much MIM. Oh well, it’s only the production environment.
This time the reason turned out to be due to changes to attribute types in the metaverse schema. One of the changes was to “convert” an attribute from a string to a boolean. It turns out that you cannot effect this change by using “Import Server Configuration” to obliterate the old config and replace with the new one, it must be trying to do some sort of delta change instead, and failing. The same probably also happens if you are trying to change an attribute from single-valued to multi-valued (see https://social.technet.microsoft.com/Forums/en-US/31ebeaf5-827a-49b9-b2a2-ebb38e63c223/error-importing-miis-server-configuration?forum=identitylifecyclemanager)
The solution is to delete the attribute(s) that are changing type, and then import the new configuration, which will recreate the attributes with the correct (new) type. Note: you can’t delete attributes until any flow rules that use them are manually removed.