August release - Failed to load expression host assembly

[Ccparkhill]

I'm receiving the following errror on a number of SSRS reports using the August 2018 release:

• Failed to load expression host assembly. Details: Could not load file or assembly 'Microsoft.ReportingServices.ProcessingObjectModel, Version=15.0.0.0, Culture=neutral, PublicKeyToken=89845dcd8080cc91' or one of its dependencies. The located assembly's manifest definition does not match the assembly reference. (Exception from HRESULT: 0x80131040) (rsErrorLoadingExprHostAssembly)

I've tried clearing the cache in both IE and Chrome but this does not resolve the issue. I have found that deleting the report and redeploying it does resolve the issue, however. 

[mgmeyer]

We just published an update that addresses this issue as well as some rendering issues, you can get it here:

https://www.microsoft.com/en-us/download/details.aspx?id=57270

[Ccparkhill]

Just looking at the Change Log and the latest version listed is:

1.3.6816.37243 (Build 15.0.2.557)

However the version I downloaded based on the announcement in this thread is:

1.3.6813.37954 (Build 15.0.2.554)

This version is not listed in the Change Log so am unsure of the differences between the two but have now upgraded to the latest build. 

Possibly others may also be unaware.  

[jamiestevens28]

Thank you

I very much appreciate the quick turnaround for the fix.  This allows us to move forward to use in production.

[messerjc]

@mgmeyer Changelog update incoming tomorrow maybe? 🙂   https://docs.microsoft.com/en-us/power-bi/report-server/changelog

[mgmeyer]

Working on it, wanted to get the bits out first 😉

[messerjc]

I can't imagine why... "Hey! The Changelog shows a new version but the download is wrong! Where's my download already Microsoft, GAWSH!"  LOL

[jtarquino]

@Ccparkhill, I'm investigating the issue, does the report that fails to render have history snapshots or caching enabled?

or its happening to all your reports regardless the features you have enabled on them.

Thanks

[Ccparkhill]

All RDL reports are now rendering sucessfully after updating the config files and restarting the service. We were not using snapshots or caching. Also, not all of our RDL reports were affected by this issue. 

When can we expect to see an updated installer? Thanks.

[mgmeyer]

We're going to try and get a patch update out for this sometime this week.

[motoray]

Any news on the patch yet?

[kelly_darren]

@Ccparkhill Did you just update part of the config files or the whole file?  @jtarquino didn't respond to my earlier query so I still don't know if we should still be looking at updating the whole file!!

Thanks

[Ccparkhill]

@kelly_darren I replaced the entire assemblyBinding section in each file with the text @jtarquino posted in message 17. 

[kelly_darren]

@Ccparkhill I missed the fact that the supplied XML was only the Assembly Binding....thats what you get for reading on a phone.  Thank you for the clarification.

[Anonymous]

I do not have caching or snapshots enabled on my paginated reports, and I am receiving the same error.

[jtarquino]

For those affected can you validate in this files 

"C:\Program Files\Microsoft Power BI Report Server\PBIRS\ReportServer\web.config"

"C:\Program Files\Microsoft Power BI Report Server\PBIRS\ReportServer\bin\ReportingServicesService.exe.config"

There is a configuration for Microsoft.ReportingServices.ProcessingObjectModel , it should look like the one below

focus in the values for oldVersion and newVersion

<dependentAssembly>
<assemblyIdentity name="Microsoft.ReportingServices.ProcessingObjectModel" publicKeyToken="89845dcd8080cc91" culture="neutral" />
<bindingRedirect oldVersion="9.0.242.0-2018.0.0.0" newVersion="2018.8.0.0" />
</dependentAssembly>

Feel free to change them and verify if that fix your issue, also if they are different that the one I showed, please post here the values you have.

Thanks

[PBIuser01]

Partial fix only ---   

We had the same issue after running the August PBIRS upgrade.  After modifying both config files following the directions outlined by jtarquino, the report builder based reports successfully loaded ( so far, for the ones we tested)

With the input from others, problem below was from the Chrome cache, that needs to be cleared out.....

Thanks  @pdbenbow, @adrez86

But,  the Power BI Desktop reports are NOT  now WORKING.  They just hang, with the 'loading data' spinning round and round.

Tried uploading the PBI Desktop reports from PBI desktop, but that did not do anything.

Now what?  did changing the ProcessingObjectModel  break the newer PBI desktop reports, while allowing the older Report Builder reports to work?  

[pdbenbow]

@PBIuser01, what browser are you using? If Chrome, I suggest you run the reports in incognito mode and see if the problem still occurs. If the reports run OK in incognito mode, then return to regular Chrome and purge your browser cache, then try again.

I experienced the same issue you're describing after completing the upgrade, as did some of our business users, but only in Chrome. Using incognito mode will give you a hint as to whether it's a problem with your browser, and purging the cache should remedy the issue.

[PBIuser01]

Thanks!!  10,000 points

[PBIuser01]

@pdbenbow   Great info - I'm running Chrome, and once I ran a sample report in incognito mode the report works.  The help desk is going to love me!

[adrez86]

Have you tried deleting the cache on the browser you're using? That worked for me on the loading hangup for BI reports