Table of Contents
Summary
- Two new validation checks for custom images will be introduced in Windows 365 to improve provisioning and service performance.
- FSLogix must not be included in newly uploaded custom images, as it will cause validation failure.
- Images must have fewer than 3,000 Start menu links; exceeding this limit will prevent the image from passing validation.
- Admins will receive error messages if uploaded images do not meet the new requirements.
- Existing custom images and current provisioning policies will remain unaffected by this change.
Admin Impact: Medium
User Impact: Low
Release Start: 01 Jan 2026
Release End: 01 Jan 2026
Services: Windows 365
Category: Plan for change
Tags: User Adoption, Admin Action
History
1/16/2026 Item Added to Message Center
Microsoft Message
Summary
Windows 365 is introducing two new validation checks for custom images. These updates help ensure consistent provisioning behavior and maintain service performance.
These validations apply only to new custom image uploads. Existing custom images already in use are not affected.
How will this affect your organization
Beginning January 2026, newly uploaded custom images must meet the following requirements:
FSLogix must not be installed
Custom images that include FSLogix will fail validation. Windows 365 manages user profile handling automatically, so FSLogix should not be included in customer-provided images.
Images must contain fewer than 3,000 Start menu links
Images with 3,000 or more Start menu items will fail validation. This limit prevents performance issues caused by extremely large Start menu structures.
This scenario is very uncommon in typical deployments.
What admins will see
If an uploaded image does not meet the new requirements, admins will see one of the following error messages:
- FSLogix detected
- Start menu exceeds 3,000 items
- Or both
No corrective action is required unless an admin chooses to update the image and reupload it.
What you need to do to prepare
No admin action is required to maintain current operations. To prepare for this change, you may choose to:
- Review internal image-building guidance and update documentation as needed.
- Ensure new images uploaded after rollout meet the updated requirements.
Additional notes:
- Existing custom images continue to function without any changes.
- Current provisioning policies are not affected.
- Only new image uploads will undergo updated validation checks.