Trending Issue: SharePoint RSS Webpart is broken after installing December 2020 CU

We received several reports that the RSS web part is broken after installing December 2020 CU.

This affects the SharePoint versions 2010, 2013, 2016 and 2019.

The error in the UI and ULS log is similar to the following:

RssWebPart: Exception handed to HandleRuntimeException.HandleException System.ArgumentNullException: Value cannot be null.  Parameter name: key    
 at Microsoft.SharePoint.WebControls.CacheObject.LoadDataFromCache(String key)    
 at Microsoft.SharePoint.WebControls.BaseXmlDataSource.GetXmlDocument()    
 at Microsoft.SharePoint.WebControls.SingleDataSource.GetXPathNavigatorInternal()    
 at Microsoft.SharePoint.WebControls.SingleDataSource.GetXPathNavigator()    
 at Microsoft.SharePoint.WebPartPages.DataFormWebPart.GetXPathNavigator(String viewPath)    
 at Microsoft.SharePoint.WebPartPages.DataFormWebPart.PrepareAndPerformTransform(Boolean bDeferExecuteTransform)

 

Update: a fix for the issue is planned to be included in the February 2021 CU.

22 Comments


  1. Well it’s good to know MS is already working on this as I patched my servers this past weekend and we’ve run into this. I don’t want to rollback the patches so we definitely need the next update to resolve this. Thanks

    Reply

    1. You can’t rollback Sharepoint patches AFAIK.

      Reply

  2. Stefan,
    Just trying to understand, does Microsoft not test basic functionality of SharePoint before releasing the patches? We have a test site where all the following functionality is configured, and it takes me less than an hour to go through and validate if the basic functionality works for them. Can Microsoft implement similar checklist and provide that all the items on the checklist passed with each PU. Something similar to me taking my car for oil change and the shop goes through 32 point inspection and providing me with the checklist of Pass/Fail with every oil change…

    Access Services
    InfoPath
    Visio Graphics Service
    RSS Feed
    IRM
    Document Sets
    List Alerts
    PHA
    Project Server
    Information Management Policy
    BDC and
    Secure Store
    User Profile Service
    Search Service Application
    Managed Metadata
    Local Term Store
    Workflow 2010
    Workflow 2013
    Excel Services
    OOS

    Reply

    1. Hi Giresh,
      Microsoft performs a large number of tests against each CU. The problem is that SharePoint includes thousands of components which can be combined in an even higher number of combinations.
      It is impossible to test every components in every combination.
      Cheers,
      Stefan

      Reply

      1. Agreed, but I consider RSS web part as a simple functionality, which should have been tested and surprised that it was broken by this PU.

        Reply

  3. Do we have a hotfix yet?

    Reply

    1. A fix is currently planned for February CU.

      Reply

  4. Hi Stefan,

    Our environment is SP 2016 and we didn’t patch our SP using December 2020 CU. But this issue happened in our environment and our RSS feeds have same error. how that happened even though we haven’t applied December 2020 CU?

    Thanks
    Yalu

    Reply

    1. Hi Yalu,
      maybe some SharePoint security fixes from December got installed automatically?
      Cheers,
      Stefan

      Reply

      1. Make sense And we are waiting the outcome of the investigation.
        Thank you Stefan!

        Reply

  5. Do you know how close MS is to resolving this issue?

    Thanks

    Reply

    1. Hi Dorrell, a fix is currently planned for February CU.

      Reply

  6. Any update on the RSS webpart fix?

    Reply

    1. Hi Abdul,
      a fix for the issue is currently planned for February 2021 CU.
      Cheers,
      Stefan

      Reply

  7. Stefan,
    Thank you for update

    Reply

  8. Hi Stefan, is there a problem installing January CU with RSS webparts whithout having December CU installed?

    Reply

    1. Hi Marcus,
      as SharePoint fixes are cumulative it is never required to install an earlier CU.
      But be aware that January CU will have the same issue as December CU as the fix is not included.
      The fix is planned for February 2021 CU.
      Cheers,
      Stefan

      Reply

      1. Many thanks to you.
        Do you have a violation for broken RSS web parts?
        Which part is not working in detail?
        Thanks in advance, stay healthy. 🙂

        Reply

        1. Hi Marcus,
          an RSS webpart added to your site will not function. Rather than showing the items from the feed it will show an error message.
          Cheers,
          Stefan

          Reply

  9. An unexpected error occurred processing your request. Check the logs for details and correct the problem. in Rss Webpart unable to fetch feed

    Reply

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