Platform SSO "Page not found" on macOS Tahoe 26.4 — Company Portal 5.2602

Environment:

• macOS Tahoe 26.4
• Company Portal 5.2602.0 (latest as of April 2026)
• Microsoft Intune — Automated Device Enrollment (ADE)
• Platform SSO with Secure Enclave (UserSecureEnclaveKey)
• SSO Extension: com.microsoft.CompanyPortalMac.ssoextension / Team ID: UBF8T346G9
• URLs configured: https://login.microsoftonline.com, https://login.microsoft.com, https://sts.windows.net
• Device: MacBook Pro 14" (Apple Silicon), supervised, ADE-enrolled

Issue:

During Platform SSO registration, after the user authenticates successfully in the SSO registration prompt, Company Portal crashes with a "Page not found" error. The registration never completes — no WPJ certificate is created, no SSO registration key is stored in the Secure Enclave.

Console logs show:

CompanyPortalMac: URL(filePath:) API misuse — usingass old file path API which does not support security scoped bookmarks

The error occurs specifically at the token exchange step after authentication, suggesting the Company Portal binary is calling a deprecated macOS file URL API that Tahoe 26.4 now enforces more strictly.

What we tried:

• Full wipe and re-enrollment via ADE
• Removing and reinstalling Company Portal via Intune
• Different user accounts
• Verified SSO extension profile is correctly applied (confirmed via profiles show -type configuration)
• Verified network connectivity to Microsoft identity endpoints
• Tested on a clean macOS Tahoe 26.4 install — same result

Expected behavior:

Platform SSO registration completes, WPJ certificate is created, and SSO token is cached for seamless authentication.

Actual behavior:

"Page not found" after authentication in the SSO registration flow. Console shows the URL(filePath:) API misuse warning. Registration fails silently — no error surfaced to the user beyond the page not found screen.

Question:

Is this a known bug in Company Portal 5.2602 with macOS Tahoe 26.4? Is there a newer build or hotfix addressing the URL(filePath:) deprecation? Any workaround available?

Tags: Platform SSO, macOS, Company Portal, ADE, Intune