Microsoft has identified a critical issue causing the classic Outlook email client to crash when users attempt to open or compose new messages. The problem specifically impacts Monthly Enterprise Channel subscribers who updated to Outlook for Microsoft 365 Version 2504 (Build 18730.20122) or later this month.
## Root Cause and Affected Systems
According to Microsoft’s support documentation, the crashes occur because “Outlook cannot open the Forms Library.” The issue predominantly affects virtual desktop infrastructure (VDI) environments, though Microsoft continues investigating the full scope of the problem.
## Temporary Workaround
Until an official fix is released, Microsoft recommends creating a missing system folder manually:
1. Close Outlook and all Office applications
2. Press Start + Run and enter: `%localappdata%\Microsoft`
3. Create a new folder named “FORMS2” in the Microsoft directory
This workaround addresses the missing folder at `C:\Users\
## Additional Outlook Issues
Microsoft is simultaneously addressing another known problem in version 2505 (Build 18827.20128) where mailbox folders flicker and move unexpectedly when users transfer items. The temporary solution involves disabling “Download Shared Folders,” though this may impact performance by forcing offline operation.
## Recent Fix History
This latest issue follows several other Outlook stability problems Microsoft has addressed recently:
– **Last week**: Fixed crashes when opening Viva Engage, Yammer, and Power Automate emails in Outlook LTSC 2019
– **Earlier this year**: Resolved crashes during email composition, replies, and forwarding
– **Ongoing**: Addressed crashes affecting Outlook and Microsoft 365 apps on Windows Server systems
Microsoft continues investigating these issues and promises updates as solutions become available. Enterprise users experiencing these problems should implement the temporary workarounds while awaiting permanent fixes.