The SQL server encountered an issue : the log disk was full
The issue was resolved by the SQL team by adding more disk space
Since the issue occurred, when Studio is launched, a message demanding an mandatory upgrade is shown.

Using Powershell, run the below commands on each of your DDC's:

Get-MonitorDatastore and Get-LogDatastore

Check for the field: Status
On each on the returned commands results. 

You may notice that the status return as "Stopped". 
If yes, then this indicates there is an issue with the datestores on the DDCs that return status as "Stopped.
These status should return as "Ok" is there is no issues. 

To resolve this issue, power off the affected DDC that is return status as Stopped. 

On the other DDC that return status as "OK" need to be rebooted. 
This will mean there may be a slight downtime so please do this when there is minimal impact. 

Once rebooted, please open up Studio and test. Issue should be resolved. 

Next bring back up the previously affected DDC and it should also work. 
 

---

Problem Cause

Studio getting message to do a mandatory site upgrade after changes were done on SQL end.