When opening nworks UI, the following error occurs:
"The given key was not present in the dictionary"
The maindb.xml file is corrupted for some reason.
It is necessary to remove the "maindb.xml" file in the following way:
Once the service is started again, "maindb.xml" will be re-created.
NOTE: Removing maindb.xml file removes all the vCenter connection configuration, each VEM server advanced property customization and VEM server ESX cluster assignments.