Forum Discussion
Experiencing random refresh errors after upgrading to Power BI RS January 2026
Hi mrusu ,
I understand how frustrating this situation must be, especially since refresh reliability is important and everything worked well before the January 2026 upgrade. Given that the issue began after the update, occurs randomly across different reports, manual refresh is successful, and changing the timeout hasn’t helped, it doesn’t seem like a misconfiguration on your end. It’s possible the new build introduced this problem.
At this stage, I don’t think it’s necessary for you to continue troubleshooting locally. I recommend submitting a Microsoft Support ticket so their team can investigate further. If it’s a build issue, that’s likely the fastest way to resolve it.
Link:Create a Fabric and Power BI Support Ticket - Power BI | Microsoft Learn
Thank you for your patience with this.
Regards,
Yugandhar
Copilot answer:
What the evidence shows
1. This is a known PBIRS issue: scheduled refresh uses stricter timeouts
Microsoft’s own community support confirms that this error is not a permissions or connectivity problem but a background refresh timeout. PBIRS scheduled refresh runs under tighter limits than interactive use, so even normal variation in refresh duration can cause failures.
2. The key setting is not ExternalCommandTimeout
PBIRS ignores ExternalCommandTimeout. The relevant setting is:
ProcessTimeout
ProcessTimeoutGcExtension
Your default is likely 300 seconds, which is too low for many refresh workloads. Increasing it to 900 seconds (or more, depending on your environment) is the recommended fix.
3. This issue became more common after PBIRS updates
Users who upgraded to newer PBIRS builds (e.g., January 2026) reported random “Failed to connect to AS” errors that disappear when refreshing manually.
How to fix it
Step 1 — Edit RSReportServer.config
Located at:
C:\Program Files\Microsoft Power BI Report Server\PBIRS\ReportServer\RSReportServer.config
Add or modify:
<ProcessTimeout>900</ProcessTimeout> <ProcessTimeoutGcExtension>300</ProcessTimeoutGcExtension>
(Values can be higher depending on your refresh duration.)
Step 2 — Restart the PBIRS service
This applies the new timeout settings.
Step 3 — Monitor refresh logs
Check:
C:\Program Files\Microsoft Power BI Report Server\PBIRS\LogFiles
Look for entries under AnalysisServicesDataRefresh to confirm timeout patterns.
🧠 Why this works
PBIRS scheduled refresh runs in a background process with a strict execution window. If your refresh sometimes takes 4 minutes and sometimes 7 minutes, a 300‑second timeout will cause intermittent failures. PBIRS then surfaces the generic error:
“Failed to connect to AS”
…but the underlying cause is simply that the refresh exceeded the allowed time.
Unfortunately this Copilot solution did not work... Still experiencing the same error ("Failed to connect to AS") even with these config file adjustments. Very exasperating issue.... There is no more guarantee reports are refreshing.....