Feature Transition: Microsoft Protected Mode for Legacy Office Files
Applicable Adept Release: All Adept releases
Intended Audience: Administrators, Organization Leaders, IT Administrators, End Users
Affected Formats: DOC, XLS, PPT (legacy Office formats)
Impact: Conditional (IT-enabled environments only)
Last Update:
Executive Summary
Adept customers may experience failures when working with legacy Microsoft Office file formats if their IT department has enabled Microsoft’s Legacy File Block - User security policy.
When this policy is active, Word, Excel, and PowerPoint cannot open or modify legacy formats, which causes certain Adept document management actions to fail.
Resolution: Convert legacy files to modern formats (DOCX, XLSX, PPTX).
Important: This does not affect all customers. Only environments where IT has explicitly enabled this Microsoft policy are impacted.
What Changed
Microsoft’s security baseline for Microsoft 365 Apps includes an optional policy (Legacy File Block – User) that blocks older binary Office formats due to security risk.
Microsoft leaves this policy off by default and recommends enabling it only after evaluating operational impact. When enabled, legacy files are blocked even in trusted locations.
Who Is Affected
A customer is impacted only if ALL of the following are true:
IT has enabled Microsoft’s Legacy File Block – User policy
The repository contains legacy Office files (
DOC,XLS,PPT)Users or automations interact with those files through Adept
Customers without this policy enabled will see no change.
Adept Impact (Legacy Files Only)
Open & Edit → Fails
Property Updates -> Fails
Data Extraction -> Degraded
Read-Only Preview -> Works
Check In -> Unaffected
Modern formats (DOCX, XLSX, PPTX) are fully unaffected.