Power BI Report Server January 2026 – msmdsrv restarts, SQLDmpr files

[JacksonWearne]

Hi,

We upgraded our Power BI Report Server to the January 2026 release and have been experiencing stability and performance issues that did not exist prior to the upgrade.

Since the upgrade, the Analysis Services process (msmdsrv.exe) appears to restart intermittently. We are seeing SQLDmpr dump files being generated, but there is no obvious crash dialog. Around the same time, users intermittently receive report rendering or upload failures. The SQLDmpr log files are large and happening around every minute, filling up the disk.

This does not appear to be a memory pressure issue, the system memory is not near exhaustion. We also do not have excessive scheduled refresh activity, and we are not seeing repeated refresh failures in the portal.

These issues began immediately after upgrading to the January 2026 build, and our workload did not materially change.

Has anyone else running the January 2026 release observed similar behavior, particularly msmdsrv restarts, sustained mashup/conhost process growth, or SQLDmpr generation tied to metadata activity? If so, were you able to identify a root cause for these errors?

Thanks

[MTerkait]

Same issue happened to us, everyhour there is 800mb of dump files generated in logfiles folder.

let me know if powerbi release a real fix.

[ArwaAldoud · Accepted solution]

Hi @JacksonWearne ,

We experienced the same issue after upgrading to the January 2026 Power BI Report Server release (msmdsrv restarts and continuous SQLDmpr dump generation).

We opened a support case with Microsoft, and they confirmed this is a known issue in this release. The product team is currently working on a fix.

Temporary Workaround (from Microsoft Support)

Until a fixed build is released, Microsoft advised deleting the generated mini dump files to prevent disk exhaustion:

Default path:
C:\Program Files\Microsoft Power BI Report Server\PBIRS\LogFiles

Delete files ending with:
.mdmp

This is only a temporary mitigation and does not resolve the root cause.

You can monitor the official PBIRS changelog for updates:
https://learn.microsoft.com/power-bi/report-server/changelog

If this response was helpful, please accept it as a solution and give kudos to support other community members

[Christoph_M]

It looks like we'll have to wait three months for the next version. Are there no bug fixes in the meantime?

Change log for Power BI Report Server - Power BI | Microsoft Learn :

There is a known issue with January 2026 PBIRS where viewing certain types of Power BI reports lead to excessive crash dumps being written to disk. This is being actively worked on and will be fixed in the next release.

[ChrisMuthmann]

There is a new build available today. I will give it a try!

• Version: 1.25.9552.1669 (build 15.0.1120.119), Released: February 25, 2026
  • Fixed issue where certain types of Power BI Reports lead to excessive crash dumps being created.

[JacksonWearne]

Thank you for this! The new build looks to be working for me!

[v-sshirivolu]

Hi @JacksonWearne   ,

After upgrading to the January 2026 release of Power BI Report Server, intermittent msmdsrv.exe restarts and repeated SQLDmpr dump files should be resolved by following Microsoft’s troubleshooting steps for embedded SQL Server Analysis Services. Ensure that your server and Power BI Desktop for Report Server versions match, and open, re-save, and republish reports using the January 2026 Desktop build to avoid metadata issues from the standard cloud version. Reset the Analysis Services workspace by stopping the Report Server service, deleting the PBIRS\ASEngine\Workspaces folder contents, and restarting the service so tabular models reload cleanly. Check the January 2026 release notes for known issues or hotfixes and apply any suggested fixes. If SQLDmpr files continue to appear, you can temporarily limit dump generation through Windows Error Reporting to prevent disk space issues while keeping samples for analysis. Also, verify that the PBIRS service account has proper read/write permissions to the installation path, ASEngine workspace, temp directories, and ReportServer databases, as permission errors can cause instability. If problems persist, Microsoft recommends opening a support case and providing SQLDmpr files, msmdsrv.log, PBIRS trace logs, and the build number. For production environments where stability is essential and the issue started after the upgrade, you can uninstall the current PBIRS version and reinstall the previous supported release, restoring encryption keys and databases to return to a stable state.

Microsoft Documentation Reference 

https://learn.microsoft.com/power-bi/report-server/

https://learn.microsoft.com/power-bi/report-server/get-started

https://learn.microsoft.com/troubleshoot/sql/tools/use-sqldumper-generate-dump-file

https://learn.microsoft.com/windows/win32/wer/collecting-user-mode-dumps

https://learn.microsoft.com/power-bi/report-server/changelog

Thank you.

[JacksonWearne]

Hi,

Thank you for your response! I have gone through all of these steps in order to troubleshoot this issue and none fixed the problem... I have found out in the meantime, that these dumps primarily occur upon uploading/rendering a report. I don't have access to open a support case.

In deleting and regenerating the workspace folder contents, the files all regenerated, but I saw the error persitst.

A similar remedy I have seen is renaming the ASEngine\workspaces folder to workspaces_old and have the report server restart rebuild that folder. I have ensured the service account has write access to ASEngine (as well as workspaces), and that does not seem to work either.

Are there any other potential solutions to this?

[v-sshirivolu]

Hi @JacksonWearne ,
If the issue persists after isolating the report and testing the above steps, this may indicate an Analysis Services engine level issue. In that case, Microsoft would need to review the generated dump files for deeper investigation.

If you have a Power BI Pro license (or your organization has a valid support plan), you should be able to raise a support ticket directly using the official process here:
https://learn.microsoft.com/en-us/power-bi/support/create-support-ticket

Even if you personally don’t have access to create a support ticket, you may want to escalate internally to your Global Admin, as they can raise a support request on your behalf.

[v-sshirivolu]

Hi @JacksonWearne ,

Could you please confirm if the issue has been resolved after raising a support case? If a solution has been found, it would be greatly appreciated if you could share your insights with the community. This would be helpful for other members who may encounter similar issues.

Thank you for your understanding and assistance.

[tayloramy]

Hi @JacksonWearne, 

Are you able to find anything in the gateway logs that might explain this? 

I just started a new job, but I had upgraded all 7 of my gateways at my previous job to Jan 2026  on January 26th (my upgrade schedule was the last monday of the month) and never saw any issues with it. 

What data sources are you primarily using? I was using mostly SQL Server and Oracle, could it perhaps be an issue with a specific connector? 

[JacksonWearne]

Hi @tayloramy, 

Thank you for your response! I only use SQL Server as my data source and everything is on-prem so I know this isn't a gateway issue.

Thanks!