I was recently trying to Upgrade the AADconnect server to stop the high 100% CPU issues
After running the
Unable to upgrade the LocalDB Sql Express database Running
I went to the event log and found the error :
Error installing msi package ‘SqlLocalDB.msi’. Full log is available at ‘C:\ProgramData\AADConnect\SqlLocalDB_Upgrade-20180813-094321.log’.
I checked through the Log and there seemed to be lots of 1603 errors
The installer then came up with the error SQL Server 2012 Express LocalDB
Could not open key: UNKNOWN\Components\. Verify that you have sufficient access to that key, or contact your support personnel.
I ran through the workaround 1 from this guide
And then the SqlLocalDB.msi finished successfully , I was then able to run through the AzureADConnect.exe upgrade