SharePoint SE KB5002908: The workflow does not start automatically

Thomas Östreich 46 Reputation points
2026-09-15T17:28:51.7033333+00:00

Symptoms

We have migrated SharePoint site collections from legacy environments (SharePoint 2013 / 2016 / 2019) to SharePoint Server Subscription Edition (SE).

Everything was running smoothly until we installed a recent Cumulative Update (CU). Following the update, standard workflows and event receivers fail to execute. The system-wide binding redirect policies deployed within the Global Assembly Cache (GAC) no longer prevent or intercept this specific issue.

When checking the SharePoint ULS logs or Developer Dashboard, the following exact error message is recorded:

LoadEventReceiverTypeSafe: Failed to load type 'Microsoft.SharePoint.Workflow.SPWorkflowAutostartEventReceiver' from assembly 'Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c'

Cause

Due to the historical migration path of the site collections, the legacy v15.0.0.0 (SharePoint 2013) assembly reference remains hardcoded directly within the registered Event Receivers' metadata inside the content database.

Resolution

To resolve this behavior, you must update the assembly binding strings stored within the affected event receivers' metadata to match the modern platform version.

The legacy assembly reference string needs to be modified from:

  • Microsoft.SharePoint, Version=15.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c

To the native SharePoint SE version:

  • Microsoft.SharePoint, Version=16.0.0.0, Culture=neutral, PublicKeyToken=71e9bce111e9429c

Once the internal metadata points to version 16.0.0.0, the hardened safe type loader successfully validates the assembly type, bypassing the block and allowing workflows to trigger as expected.

Microsoft 365 and Office | SharePoint Server | For business

1 answer

Sort by: Most helpful
Most helpful Newest Oldest
  1. Jay1 Tran 695 Reputation points Independent Advisor
    2026-09-15T17:36:39.6566667+00:00

    Hi Thomas,

    Thank you for taking the time to share this detailed information.

    I appreciate you documenting the specific behavior regarding the LoadEventReceiverTypeSafe error and the hardened safe type loader in SharePoint Server Subscription Edition (SE).

    Your explanation regarding the hardcoded Version=15.0.0.0 assembly references within the content database metadata is extremely helpful. This context clarifies why standard GAC binding redirect policies may fail to intercept the issue after a Cumulative Update, and it provides a clear path forward for resolving these legacy migration artifacts.

    I value this contribution to the community, as the specific steps to manually update the assembly binding strings to Version=16.0.0.0 will likely assist other users encountering similar workflow and event receiver failures during their migration from SharePoint 2013/2016/2019.

    Thank you again for sharing your findings. Wishing you a great day ahead.

    Was this answer helpful?

Your answer

Answers can be marked as 'Accepted' by the question author and 'Recommended' by moderators, which helps users know the answer solved the author's problem.