topic Re: An unexpected error occurred (file '', line , function '') in Report Server

An unexpected error occurred (file '', line , function '')

Nuno_Santos — Sat, 07 Jun 2025 05:54:18 GMT

After updating to the May 2025 Report Server, the error 'An unexpected error occurred (file '', line , function '')' is occurring in reports that had been deployed for a long time.

It appears that the issue might be related to date Slicers. Ig o delete the date slicer visual and redeploy, the error is gone.

Re: An unexpected error occurred (file '', line , function '')

Nasif_Azam — Sun, 08 Jun 2025 07:00:58 GMT

Hey @Nuno_Santos ,

The error message:

An unexpected error occurred (file '', line , function '')

after updating to the May 2025 version of Power BI Report Server (PBIRS), particularly triggered by date slicers, appears to be a regression or compatibility issue introduced in the new release.

Root Cause (Based on Behavior)

Since you mentioned: "If I delete the date slicer visual and redeploy, the error is gone."

this strongly points to a breaking change in how date slicers are processed/rendered in the May 2025 version.

This issue has been observed in previous updates as well, where:

Report visuals created using older versions of Power BI Desktop (especially slicers with relative or hierarchical filtering) break after a server update.
Sometimes serialized visuals (like date slicers) fail to rehydrate properly due to a schema or engine update.
Certain slicer configurations might not be supported anymore or require a fresh re-creation from the latest Power BI Desktop for Report Server.

Recommended Workarounds

Use the Matching May 2025 Power BI Desktop for PBIRS
Ensure you’re editing reports with the same version of Power BI Desktop that corresponds to May 2025 PBIRS. Do not use the standard (cloud) Power BI Desktop version.
Download from Microsoft (check for "Power BI Desktop (Report Server)" – May 2025 version)
Delete and Recreate the Date Slicer
As you already noticed, recreating the slicer eliminates the error. To minimize future issues:
- Use the "Between" mode rather than relative date slicers.
- Avoid any deprecated or custom slicer visuals.
Test with Static Dates or Basic Filters: If date ranges are not mandatory for interaction, consider using dropdown or list slicers temporarily.
Review Report Logs: Enable and check PBIRS logs (RSHostingService.log) for more detailed stack traces that might indicate failing visual components.
Long-Term Fix:
If the issue is confirmed as a bug introduced in the May 2025 PBIRS, Microsoft will likely address it in the August or September 2025 update. Keep an eye on:
- Microsoft Power BI Report Server Blog
- Power BI Community Forums
Temporary Mitigation: If this issue affects multiple reports:
- Batch reprocess slicers using a macro/script to regenerate affected visuals (if many reports are involved).
- Report the bug to Microsoft via their support channel with reproduction steps and logs.

If you found this solution helpful, please consider accepting it and giving it a kudos (Like) it’s greatly appreciated and helps others find the solution more easily.

Best Regards,
Nasif Azam

Re: An unexpected error occurred (file '', line , function '')

Poojara_D12 — Mon, 09 Jun 2025 05:23:24 GMT

Hi @Nuno_Santos

After updating to the May 2025 version of Power BI Report Server, you are encountering the error message 'An unexpected error occurred (file '', line , function '')' in long-standing reports, and the issue appears to be tied specifically to date slicer visuals. This kind of error typically indicates a rendering or compatibility issue introduced by changes in the underlying visual or report server engine. Microsoft periodically updates the slicer functionality—especially for date-based slicers—to enhance usability or performance, and these updates can inadvertently break backward compatibility with older visuals that were created or configured differently in previous versions of Power BI Desktop optimized for Report Server.

The fact that deleting and re-adding the date slicer resolves the error strongly suggests that the issue is with how the slicer metadata is stored in the report file, and that the updated server cannot correctly interpret or render the older slicer configuration. This is not uncommon when reports built with earlier Desktop versions are redeployed to a server with a newer rendering engine. To address this, the most reliable workaround is to open the affected report in the May 2025 version of Power BI Desktop (for Report Server), delete and re-add the date slicers, then re-publish the report. This ensures that slicers are regenerated using the latest structure compatible with the updated server version. Until Microsoft releases a patch or acknowledges this as a regression, this manual refresh of slicers is likely the safest way to ensure report stability.

Re: An unexpected error occurred (file '', line , function '')

Nuno_Santos — Mon, 09 Jun 2025 10:08:57 GMT

Hi,
thank you for your comments, but even after removing and rebuilding the slicer, the error persists. I’ve rebuilt the report from scratch using the latest available version of Power BI Desktop Report Server (2.143.954.0 64-bit ( 2025 may)), and the error still occurs.
What’s also strange in this situation is that I have a standalone server with SQL Server 2022 and the May version of Power BI RS where the error does not occur. But in a two-server Always On setup with SQL Server 2022 and the May version of Power BI RS, the error does occur...

Re: An unexpected error occurred (file '', line , function '')

Anonymous — Mon, 09 Jun 2025 12:49:24 GMT

Hi @Nuno_Santos ,
Thank you for the follow-up!

Thanks for letting us know what you tried. Since rebuilding the slicers and the whole report did not solve it.Please follow the belw steps:

Check the report server logs on the Always On servers to see if there is more info about the error.
Take a look at your SQL Server Always On setup, sometimes connection or failover might cause weird issues.
If possible, try pointing the report server temporarily to your standalone SQL Server and see if the error goes away.
Also, make sure all your servers and software have the latest updates and patches installed.

Hope this resolve your query.If so,consider accepting it as solution.

Thank you.

Regards,
Pallavi.

Re: An unexpected error occurred (file '', line , function '')

Nuno_Santos — Mon, 09 Jun 2025 13:37:14 GMT

Hi,

All servers have the latest updates and patches. All Sql Serves are in 16.0.4195.2 (2025 may).
Log is in verbose mode but give no more details:
- 2025-06-09 14:14:43.8255|ERROR|114|An error occurred running the query.Details: ErrorCode=QuerySystemError, ProviderErrorCode=0xC1000000, ErrorSource=PowerBI, Message=Failed to execute the DAX query., HResult=0x80004005, Language=en-US, ProviderErrorMessage=[<ccon>An unexpected error occurred (file '', line , function '').</ccon>], ProviderGenericMessage=[Internal error: An unexpected error occurred (file '', line , function '').], ErrorSourceOrigin=MsolapWrapper, AS, OnPremErrorCode=, InnerErrorDetails=[Type=MsolapWrapper.MsolapWrapperException, Message=Failure encountered while executing the DAX query.]| RequestID = 7d5a340b-9999-3d1e-9999-3zzxxvvbbnn1 ClientSessionID = 7d5a340b-9999-3d1e-9999-3zzxxvvbbnn1
- 2025-06-09 14:14:43.8305|INFO|114|Writing error DSR| RequestID = 7d5a340b-9999-3d1e-9999-3zzxxvvbbnn1 ClientSessionID = 7d5a340b-9999-3d1e-9999-3zzxxvvbbnn1
I compared the configuration between the standalone and Always On solutions but didn’t find anything also.

Re: An unexpected error occurred (file '', line , function '')

Nuno_Santos — Mon, 09 Jun 2025 16:31:08 GMT

each time error occurs one event is raised:
The description for Event ID 22 from source MSOLAP$PBIRS cannot be found. Either the component that raises this event is not installed on your local computer or the installation is corrupted. You can install or repair the component on the local computer.

Re: An unexpected error occurred (file '', line , function '')

Anonymous — Tue, 10 Jun 2025 10:21:12 GMT

Hi @Nuno_Santos ,

Please go through the mentioned steps and check step by step again ,if still faces the same issue then please consider raising a support ticket for further assistance.

To raise a support ticket for Fabric and Power BI, kindly follow the steps outlined in the following guide:

How to create a Fabric and Power BI Support ticket - Power BI | Microsoft Learn

If this post helps, please give us Kudos and consider marking it Accept as solution to assist other members in finding it more easily.
Thank you for being a part of Microsoft Fabric Community Forum!

Regards,
Pallavi G.

Re: An unexpected error occurred (file '', line , function '')

Anonymous — Thu, 12 Jun 2025 11:59:51 GMT

Hi @Nuno_Santos ,
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.

Re: An unexpected error occurred (file '', line , function '')

Nuno_Santos — Thu, 12 Jun 2025 13:33:36 GMT

Hi,

I raised a support case and i'm waiting for a solution.

I restored the database from the server that has the error onto the server that is working fine, and it worked well. So I assume the issue is not with the database. At this point, I haven’t made any progress and I’m waiting for updates from support or a patch from the May 2025 version of Power BI Report Server.

Thank you.

Re: An unexpected error occurred (file '', line , function '')

lstanczyk1 — Thu, 12 Jun 2025 15:06:04 GMT

Can you tell me more about your macro/script idea?

Re: An unexpected error occurred (file '', line , function '')

Anonymous — Fri, 13 Jun 2025 07:18:00 GMT

Hi @Nuno_Santos ,
We appreciate your patience and thank you for the update on the issue. A dedicated support team will be assigned to handle the scenarios efficiently. Please wait until the issue is resolved. Once resolved, kindly share the insights and mark them as "Accept as Solution" to assist others with similar issues.

Thank you.

Re: An unexpected error occurred (file '', line , function '')

wangpipi — Mon, 16 Jun 2025 05:43:56 GMT

我们遇到了相同的问题，正在等待微软的回复

Re: An unexpected error occurred (file '', line , function '')

jimmylin829 — Fri, 20 Jun 2025 16:15:38 GMT

It's broken for us as well and adding the date slicer back in doesn't resolve the issue 100% of the time. Unfortunately we wont be moving forward with the May 2025 update until this is fixed

Re: An unexpected error occurred (file '', line , function '')

jimmylin829 — Fri, 20 Jun 2025 16:16:23 GMT

@Nuno_Santos did you get a resolution from Microsoft on this? Thank you!

Re: An unexpected error occurred (file '', line , function '')

Nasif_Azam — Fri, 20 Jun 2025 16:31:48 GMT

Hey @lstanczyk1 ,

If you are dealing with several reports that have slicer-related issues, automating the slicer recreation can save you significant time. To automate recreating date slicers across multiple reports using macro/script, you can use the following methods:

PowerShell Script: Automate the process of identifying, removing, and recreating date slicers in multiple PBIX files, then republish the updated reports.
Power BI REST API: Write a custom script to interact with Power BI reports, replacing the date slicers programmatically and automating the update process.
Template Approach: Create a reusable Power BI template with the correct slicer configuration, then copy visuals into other reports.
Third-Party Tools: Use tools that can batch-edit PBIX files, allowing for easier slicer management across multiple reports.

For Detailed Information:

PowerShell Scripting for Power BI

Power BI REST API Documentation

Automate Power BI Service with Power Automate

PBIX File Editor Tool

If you found this solution helpful, please consider accepting it and giving it a kudos (Like) it’s greatly appreciated and helps others find the solution more easily.

Best Regards,
Nasif Azam

Re: An unexpected error occurred (file '', line , function '')

Nuno_Santos — Fri, 20 Jun 2025 17:15:39 GMT

Not yet.

Re: An unexpected error occurred (file '', line , function '')

Anonymous — Fri, 27 Jun 2025 09:02:28 GMT

Hi @Nuno_Santos ,
We are following up once again regarding your query. Could you please confirm if the issue has been resolved through the support ticket with Microsoft?
If the issue has been resolved, we kindly request you to share the resolution or key insights here to help others in the community.

Thank you for your understanding and participation.

Re: An unexpected error occurred (file '', line , function '')

Nuno_Santos — Fri, 27 Jun 2025 09:53:58 GMT

Hi, still working on it.

I have run some tests and minimized the data to reproduce the error with a CSV file, created in a plain text file.

The text file contains only these lines:

A,B

1845,330679

the 3 steps applied to file load:

= Csv.Document(File.Contents("D:\work\TestFile.csv"),[Delimiter=",", Columns=2, Encoding=65001, QuoteStyle=QuoteStyle.None])

= Table.PromoteHeaders(Source, [PromoteAllScalars=true])

= Table.TransformColumnTypes(#"Promoted Headers",{{"A", type number}, {"B", Int64.Type}})

column A was set as a decimal and column B as a whole number.

I created the measure:

measure= CALCULATE(COUNT(TestFile[B]),TestFile[A]>0)

and a visual list with only one column containing the created measure and the error occurs.

the error disappears if I do one of the following:

remove at least one line of the file (all lines are equal)
change column A type from decimal to whole number
change measure removing TestFile[A]>0, or changing to TestFile[A]=0 or TestFile[A]<0, but TestFile[A]>=0 the error remains (the '>' operator is causing the error)

Thanks.

Re: An unexpected error occurred (file '', line , function '')

Anonymous — Fri, 27 Jun 2025 10:51:56 GMT

Hi @Nuno_Santos ,
Thank you for keeping us updated on the issue and confirming that it’s still unresolved. Once you hear back from the support team, please do share the response here, it will be helpful for others who may encounter a similar issue.
Thank you.

topic Re: An unexpected error occurred (file '', line , function '') in Report Server

An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Root Cause (Based on Behavior)

Recommended Workarounds

Temporary Mitigation: If this issue affects multiple reports:

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')

Re: An unexpected error occurred (file '', line , function '')