Fix: Regression in September 2020 CU for SharePoint 2019 affects sites with modern UI

Microsoft has released a fix to address the regression introduced with September 2020 CU for SharePoint Server 2019.

If you did not install September CU you can skip installing KB 4484505 and use the fix below instead. If you already installed KB 4484505 you can install KB 4461512 on top of it to resolve the issue.

 

KB article and download link for the fix can be found here:

 

Important: You have to install KB 4484504 together with this update if you did not install it earlier, otherwise, some features won’t work.

As with all SharePoint fixes you have to run the SharePoint configuration wizard after applying the fix.

15 Comments


  1. Hi Stefan,
    do I need to run the Configuration Wizard on each machine after installation?

    Reply

    1. Hi Tobias,
      yes. All SharePoint fixes require to run the config wizard.
      Cheers,
      Stefan

      Reply

  2. Hi Stefan, thanks for this.

    Is it enough to apply this fix only (instead of the core one, KB 4484505) together with the language dependent (KB 4484504) or do I need to install the original one (KB 4484505), then this fix (KB4461512) and lastly as the 3rd one KB 4484504?

    Thanks in advance.

    Regards,

    Gonçalo

    Reply

    1. Hi Gonçalo,
      as I wrote above: “If you did not install September CU you can skip installing KB 4484505 and use the fix below instead. If you already installed KB 4484505 you can install KB 4461512 on top of it to resolve the issue.”
      Cheers,
      Stefan

      Reply

      1. Thanks Stefan.

        When I install the patches, I normally run the configuration wizard on the 1st AppSrv alone until it finishes (update of DB schema) and then all the other servers one after the other. Can I do all the servers at the same time?

        Thank you.

        Regards,

        Gonçalo

        Reply

        1. Hi Gonçalo,
          you need to run PSConfig on one server to do the db schema update – do not run this step in parallel on multiple machines.
          After this is completed you can start the config wizard on the remaining machines in parallel.
          Cheers,
          Stefan

          Reply

          1. Perfect. Thank you Stefan.
            Cheers,

            Gonçalo


          2. Interesting or not Stefan, after applying it on the AppSrv1, I went to the other servers to do it in parallel, so I started WFESrv1 and when I started WFE02 it is still on 1 of 10, with message ‘waiting to get a lock to upgrade the farm’.

            Cheers,

            Gonçalo


  3. Hello there,
    I can confirm, after installing the fix on our test farm, that the issue related to modern sites is gone (aka is corrected). But the second issue related to some search settings pages (in site settings) is not resolved. Just to inform other admins… Despite our prod farm is using classic experience I decided to hold off these september updates and rather implement august updates, till the october CU is published and settled down – aka let the others to find new issues, if they will appear.
    Good luck to everyone.
    Ladislav

    Reply

    1. Hi Ladislav,
      that is correct – this critical on demand fix only addresses the modern site issue. The search issue is still listed in the “Known issue in this update” section of KB 4461512.
      Cheers,
      Stefan

      Reply

  4. Hello,

    we are facing issue 2 of KB 4484505 with SharePoint 2013

    “Issue 2

    An error occurs when you try to access the “Result Sources,” “Query Rules,” “Search Result Sources,” or “Search Query Rules” page from the Search Settings section of Site Settings. ”

    Is this known thill now? Site did not open in Central Admin after installing September CU for SP2013.
    Could not find any information/regression at MS.

    Gruß
    Christian

    Reply

    1. Hi Christian,
      yes this affects SP2013 as well. The fix is currently planned for October CU.
      Cheers,
      Stefan

      Reply

  5. Hi Stefan, thank you for these updates. We had to work the whole night to fix the farm of one of our customers so im not so happy with the last few Microsoft updates for SP2019 but your info did save the day…or night 🙂 We had still some problems with news webparts after these fixes. No text was shown, only pictures but this was fixed when you place the webparts again on the page. The only bug left is that if you click in the news webpart on ‘all the news’, the news.aspx page is also not showing text, only pictures. How can we fix this page?

    Reply

    1. Hi Auke,
      sorry – I’m not sure. Haven’t used this web part and we I have not seen any cases matching the description you provided.
      I would recommend to open a ticket with Microsoft to get this analyzed.
      Cheers,
      Stefan

      Reply

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