I've spent hours researching this and to no avail. We've upgraded SQL Server 2016 to 2017 and detached the ReportServer db as part of this process. After installing SSRS v14.0.6514.11481 and pointing to the restored ReportServer db it worked perfectly.
The problem came when we tried to upgrade to PBIRS. Recieved this message when navigating to the localserver/Reports portal:
Checked the logs and it said:
ERROR: Database downgrade detected. The database schema version is newer than service schema version.
Not sure how to proceed here. Why would the db schemas be incompatible?
Trying to complete this process for reference:
Did you install both SSRS instance and Power BI Report Server on your machine? If so, did you use a single ReportServer DB for both SSRS and PBI report server?
You should create two separate reportserver databases for SSRS and PBIRS.
I have the same issue. Were you able to solve it?
My SSRS native databases come from SQL Server 2017 CU4.
I restored them on a new instance, where the Power BI Report Server is installed. This is the latest version (14.0.600.442).
The web service works (so the server can connect to the database), but the portal won't work, giving the error provided in this thread.
I ended up contacting a Microsoft tech and through hours of troubleshooting found that I should not have connected to a different edition of SSRS before connecting Power BI Report Server. See response below:
The ReportServer that is being migrated has likely been connected to a different edition of SSRS. Power BI Report Server cannot connect to a ReportServer database that has been upgraded from SSRS 2016 to SSRS 2017, as the database schemas are not compatible. Scale-out deployment is also not possible using both SSRS and PBIRS
This may not be your issue, but it was for me. I think the ambiguous error messages made this difficult to realize for a novice like me.
I finally solved the issue and it was indeed because the databases are not compatible. I blogged about the solution here: http://sqlkover.com/migrate-ssrs-2017-to-power-bi-report-server/. In short: there's some table with an incorrect build number and the database schema isn't supported.
Personnally, I find the explanation of the Microsoft employee lacking. The documentation states it's possible to upgrade from SSRS 2012 and later to Power BI Report Server. In my case even, it was from a straight SSRS 2017 installation (so I did not upgrade from SSRS 2016 to 2017).
Check this blog :