Once resolved, follow these best practices to avoid seeing the error again:
: Add the Dolphin executable and its user folder (usually found in Documents\Dolphin Emulator ) to your antivirus exclusion list. Adjust Windows Security : Navigate to Virus & threat protection Manage settings Manage Controlled folder access dolphin iosfs failed to write new fst
The error message "IOS_FS: Failed to write new FST" in the Dolphin Emulator typically occurs when the emulator cannot modify or create system files in its data directory. This is most often a permissions issue antivirus interference Primary Solutions Check Folder Permissions Once resolved, follow these best practices to avoid
. This forces Dolphin to store all user data in its local directory instead of the system's Documents folder, which can circumvent many permission issues. This forces Dolphin to store all user data
If you've encountered the "IOS_FS: Failed to write new FST" error while trying to launch a game or open the Dolphin Emulator , you're likely facing a permissions or access conflict . This error typically occurs when the emulator is blocked from writing essential system files to its user directory. Why Does This Error Occur?