Microsoft officially announced the retirement of the SharePoint Add-In model and the Azure ACS authentication mechanism on April 2, 2026.

These two components are closely related. Most SharePoint Add-ins (especially those that work in the cloud) use Azure ACS for authentication. And when support for one ends, the other stops working.
 

For businesses, this means that from April 2, 2026, all the solutions built on this technology will stop working in SharePoint Online.

Below are the key facts and recommendations for Users for the few weeks remaining until April.

The reasons

In November 2023, Microsoft officially announced the gradual shutdown of the SharePoint Add-In model and Azure ACS in the Microsoft 365 cloud. Among the key reasons, the Corporation named:

• Security and optimization: Fewer outdated components mean fewer risks. New mechanisms (SPFx, Graph API via Entra ID) are better secured and easier to administer.
• Platform unification: Microsoft is focused on developing a single approach to SharePoint extensions through SPFx and integration with Teams. Supporting two parallel models (Add-In and SPFx) no longer makes sense.
• Better experience for Users: SPFx allows you to create a more seamless interface in SharePoint (in the Modern UI style), while add-ins often looked «alien» or required switching to separate pages.

The key dates

From the end of 2023, Microsoft stopped developing SharePoint Add-In (the model was declared deprecated) and set the end of support:

• From July 1, 2024, it is no longer possible to install new add-ins from the public SharePoint catalog (Marketplace). The Add-In store is effectively shutting down.
• From November 1, 2024, add-ins and ACS no longer work for new Microsoft 365 Customers. (That is, if the Organization is created in M365 after this date, it can no longer use the old model.)
• April 2, 2026, is the last day of life of Add-Ins and Azure ACS in the cloud: in all Microsoft 365 tenants, these services will be completely disabled. After that, any add-in in SharePoint Online will simply stop working.

Therefore, for many Organizations that still use the old solutions, these changes may come as an unpleasant surprise. So, you need to prepare in time.

As for LS Intranet 2.9

Given these prospects, we have not released new versions of LS intranet 2.x line of the Internal Corporate Portal for several years, focusing instead on the next generation of the product. That is, as of now, LS Intranet 2.9 is in support mode, receiving no significant feature updates.

The final shutdown of LS Intranet 2.9 in Microsoft 365 will take place on April 2, 2026. Since then, this version of the portal will not work in Microsoft 365 due to reasons beyond our control (namely, due to the disabling of the Add-In model at the Microsoft platform level).

However, we already have a ready-made solution that will ensure continuity of work for our Customers and provide new functionality.

Why the transition to LS Intranet 3.0 is mandatory

LS Intranet 3.0 Internal Corporate Portal is implemented as a separate web app on the Customer's domain and uses the SharePoint platform only as a data repository, but with simplified classic administration. That is, it does not require in-depth knowledge of SharePoint to work.

In other words, LS Intranet 3.0 is an independent web portal that:

• Integrates with Microsoft 365 in modern ways. Instead of Azure ACS, it uses Microsoft Entra ID (Azure AD) for authentication and access to SharePoint data. This is consistent with Microsoft's recommendations to rewrite add-ins as separate SaaS apps with authentication via Entra ID.
• Has its own modern interface. The portal runs on a modern web development stack, which provides a fast, responsive design. It looks different than standard SharePoint, and this allows us to avoid the limitations of the old interface. At the same time, data (documents, lists) can be stored in your SharePoint Online – that is, the entire content base remains with you.
• Easier to administer. By abandoning the Add-In model, we were able to make the admin panel more user-friendly. For example, Content Managers can post publications using templates. Or drag and drop widgets with the mouse, without going into complex SharePoint settings.
• Richer in integration. LS Intranet 3.0 easily works with Teams, Outlook, and other Microsoft 365 tools. Integration with our AI-UniBot Personal Assistant & Corporate Chatbot, functioning on the basis of Artificial Intelligence, is provided. The modules of news, ideas, surveys, etc., were modernized.
• Ready for improvement. We are enthusiastically updating 3.0, adding new features, from custom emojis to AI elements. This platform grows with the needs of your Business.

It is important to note that LS Intranet 3.0 does not have dependencies that will cut off its life in a few years. After all, its architecture corresponds to the development trends of Microsoft 365.

One of the first Users of LS Intranet 3.0 became JSC «Ukrnafta». Their previous corporate portal worked on LS Intranet 2.9. The update to 3.0 provided Users, among other improvements, with a modern design and more flexible integrations, an intuitive interface that adapts to mobile devices. The IT department gained confidence that the solution would continue to work stably, despite changes in Microsoft policy.

What to do now

To avoid discontinuing the processes, loss of access, and inevitable downtime, we recommend implementing the following action plan as soon as possible: 
1. Audit your SharePoint environment to determine:

• Which solutions are built as Add-ins.
• Where Azure ACS is used.
• What exactly will stop working after April 2, 2026.

2. Plan migration to modern technologies. 
If you need expert help for this, please do not hesitate to contact us. After all, we have extensive experience in moving from Add-in architecture to modern solutions. Including transferring data, integrations, settings, and work scenarios.

3. Be sure to upgrade to LS Intranet 3.0 if you have LS Intranet 2.9 installed. 
Please contact us immediately and learn about proven migration scenarios.

In short, we are ready to help you with the implementation of any point of your migration plan. However, it is important not to delay key decisions. After all, there are only a few weeks left until April 2!