We are currently learning of an emerging issue linked to the latest Windows 11 update (Build 26100.6899), released on 14th October 2025.
Issue Summary:
While the API service remains active and running on this Windows build, no endpoints will be available. This upgrade will affect customers using Act! Premium Desktop & Cloud with Desktop Sync. As a result, the following features and areas will fail, and errors may occur.
- Welcome
- Insights
- KPI & Pipeline
- Outlook integration
- Word Integration
- Contact & Calendar Synchronization
Keystroke has produced a bat file that can be downloaded here to roll back these two Windows updates:
https://www.act4work.com/files/Scripts/
We've gotten reports that simply reinstalling your Act! Premium software will fix the issue, but this is not confirmed. Act! has published dedicated articles on both the Desktop and Cloud Knowledgebases to help resolve the current issue.
Desktop - API Features, Home Page Opportunity KPI’s, Act! Insight or Outlook Integration Fail For Remote Databases After Installing Windows Update Win 11: 26100.6899
- https://help.act.com/s/article/API-Features-Home-Page-Opportunity-KPI-s-Act-Insight-or-Outlook-Integration-Fail-For-Remote-Databases-After-Installing-Windows-Update-Win-11-26100-6899-prem?language=en_US
Act! Cloud (remote databases) - API Features, Home Page Opportunity KPI’s, Act! Insight or Outlook Integration Fail For Remote Databases After Installing Windows Update Win 11: 26100.6899
