Server 2019 RD-Connectionbroker Rolle broken after Windows Update

SvPeters 

Sounds like a similar case I had last year, but with a slight different setup.

For my customer I was running a 3 server RDS Remote App farm HA setup (all 3 servers were configured as Session Host with Web Access and RDCB role linked to an external SQL Database).

I was performing regular update maintenance and after restarting the servers, I could not login to any of the remote apps. Upon inspection of the logs I noticed similar errors (relating to NULL references).

Unfortunately after a few nightly hours of troubleshooting, I could not find and fix the error and  ended up reinstalling the entire RDS farm so that the users could go back to the work the next morning.

Since you can recover a working RDCB, try the following:
- Restore from backup

- Before restoring domain trust with a reboot (which also breaks it again), install SQL Server Management Studio on your RDCB broker

- Connect to WID Database by connecting to the following address in SQL Studio (must be ran locally on RDCB since WID is not externally reachable):

 \\.\pipe\MICROSOFT##WID\tsql\query

- Create a backup of your RDCB database from your WID

- Restore domain trust by rebooting and installing update

- Restore WID backup via SQL Studio on WID or if you would like to go HA, restore the database backup to your SQL server.

If that does not work (especially when you chose to keep working with WID), be sure to check of TLS 1.0 was not disabled with the update. WID needs it to work.