Since multiple Trending Issues have now been documented for the September 2025 CU, and it’s becoming increasingly difficult for individuals to keep track, I’ve decided to create a single summary page. Issue Status SharePoint 2013 Workflows fail in combination with Classic Microsoft Workflow Manager after September 2025 CU Warning: Upgrade to SPWFM required before July […]
To enhance security of SharePoint Server, three new security features are being introduced in September 2025 CU. These enhancements apply to all supported SharePoint versions — 2016, 2019, and Subscription Edition — and I’d like to highlight them in this article: Machine Key Rotation Timer job AMSI enabled for all web applications Test-DefenderAndAmsiWorkProperly Cmdlet to […]
The 25H2 feature update for SharePoint Server Subscription Edition has been released today and is included in the September 2025 CU for SharePoint Server Subscription Edition. About Feature Updates for SharePoint Server Subscription Edition: Releasing new features for a product which is used by a large number of users creates challenges for IT departments, e.g. […]
In discussions with customers about the current situation — where active attacks are targeting on-premises SharePoint servers — it has become clear that additional clarity is needed regarding how AMSI integration works in SharePoint. Here are some of the questions we’ve received: Question: How can we verify if AMSI is working correctly in SharePoint […]
Microsoft is aware of active attacks targeting on-premises SharePoint Server (2016, 2019, Subscription Edition) customers by exploiting vulnerabilities partially addressed by the July Security Update. SharePoint Administrators are advised to check there SharePoint machines for a file named spinstall0.aspx in the …\16\TEMPLATE\LAYOUTS directory. If this file exists the machines are most likely already affected. Microsoft […]
The 25H1 feature update for SharePoint Server Subscription Edition has been released today and is included in the March 2025 CU for SharePoint Server Subscription Edition. About Feature Updates for SharePoint Server Subscription Edition: Releasing new features for a product which is used by a large number of users creates challenges for IT departments, e.g. […]
Since release of September 2023 CU we received a couple of support cases where all web applications stopped working with a 500 server error. A similar problem related to problems coming from Antivirus Scanners was discussed in my previous article. In a couple of cases we identified a second problem with similar symptoms but different […]
With September 2023 CU the AMSI security feature for SharePoint Server 2016, 2019 and Subscription Edition has been automatically enabled for a customers. After the activation of this feature a couple of customers have reported application pool crashes and 500 server errors. Background info The Windows Antimalware Scan Interface (AMSI) is a security feature introduced […]
April 2023 CU includes the new AMSI security feature for SharePoint Server 2016 (see here for details). This functionality caused problems on SharePoint Server 2016 machines installed on top of Windows Server 2012 R2 as AMSI relies on functionality in the Windows operating system which is only available in Windows Server 2016 and later. With […]
With Feature Update 22H2 last November we added AMSI support for SharePoint Server Subscription Edition. Today with March 2023 CU for SharePoint Server 2019 we have added the same functionality to SharePoint Server 2019. Excerpt: The cybersecurity landscape has fundamentally changed, as evidenced by large-scale, complex attacks, and signals that human-operated ransomware are on the […]
In previous versions of SharePoint Server new features were introduced with the release of new major versions. Those versions would be serviced with new security and quality improvements via monthly Public/Cumulative Updates but only on rare occasions, new feature experiences may be introduced via a Public/Cumulative Update. Unlike earlier versions SharePoint Server Subscription Edition is […]
