Mendix Studio Pro Partial Outage due to Windows 11 October 14 Update

Incident Report for Mendix Technology

Resolved

After closely monitoring the issue with existing customers and new incidents, we can confirm that the latest patches from Microsoft resolved the issue that was introduced.
Posted Oct 22, 2025 - 06:12 UTC

Monitoring

The current solution to this issue is to install "Security Intelligence Update for Microsoft Defender Antivirus - KB2267602 (Version 1.439.210.0)".

This has solved current running incidents, but we are narrowly monitoring this with our customers to make sure all issues are resolved.
Posted Oct 17, 2025 - 12:06 UTC

Investigating

With the October 14 update of Windows 11, Studio Pro 9, 10, and 11 can show errors in different panels and editors making it unusable.

When you see the message "Hmmm... can't reach this page" with an error code of `ERR_CONNECTION_RESET`, in a tool panel or editor, your workstation is likely affected. Example panels where it can occur are the design properties and toolbox. Example editors are the Microflow, Nanoflow and Rule editor.

The current known workarounds for this problem are:
- Install "Security Intelligence Update for Microsoft Defender Antivirus - KB2267602 (Version 1.439.210.0)"
or
- Uninstall the following Windows updates: KB5066835, KB5066131, and KB5065789

We are actively investigating this issue and will update regularly.
Posted Oct 15, 2025 - 16:37 UTC
This incident affected: Mendix Services (Studio Pro).