Report Server prompts for credentials after changing parameter

[iNenadnano]

After upgrading Report Server to the latest release (September 2021), a strange issue has started showing up for some users. The issue is as follows:

• user opens a paginated report with default parameters without any issues
• user modifies a parameter in the report, clicks "View Report", after that they are prompted for credentials and none of the credentials work (either their own or the one of a system administrator)

Domain users have browser role to reports in question, and the reports are using the same data source which is configured to use a service account to access the SQL Server holding the data. I am unable to reproduce the issue on my end, and am out of ideas for troubleshooting this.

Any ideas community?

Thanks!

EDIT: Forgot to mention originally, Report Server is behind Caddy as a reverse proxy and I believe that it might be causing the problems after all, I am just unsure what the problem might be given that all worked as expected with the same configuration with previous version of Report Server.

[v-janeyg-msft]

Hi, @iNenadnano 

Does some users have problems, and some users are still normal? Can the report be refreshed normally?
Have you checked the firewall settings, http ports 80 and 443 are open?

Did I answer your question ? Please mark my reply as solution. Thank you very much.
If not, please feel free to ask me.

Best Regards,

Community Support Team _ Janey

[FarhanAhmed]

What is the Authentication Method applied to Data Sources?

After Upgrading did you restored the Encryption keys of the database?

[iNenadnano]

Hi @FarhanAhmed,

Data sources are accessed using dedicated SQL server credentials without impersonation. Report server itself uses NTLM authentication.

I do not remeber being asked to backup and restore encryption keys during the upgrade.

One more thing to keep and mind that I have forgotten to mention, Report Server is behind Caddy as a reverse proxy and I believe that it might be causing the problems after all.

[FarhanAhmed]

Actually, encryption keys are used to encrypt sensitive information that is stored on PBI Report Server. i.e. Connection String, User credentials, Schedule refresh information etc.

You can view this option when you execute PBIRS Configuration under Encryption Keys  

Back Up and Restore Reporting Services Encryption Keys - SQL Server Reporting Services (SSRS) | Micr...