Short-term mitigations
Ensure Dolphin has been granted full storage permissions in your device settings. Windows (Wii NAND issues)
: On Android 11 and 12, stricter "Scoped Storage" permissions can prevent the emulator from writing to the NAND if it's stored on an SD card or a restricted internal folder. Common Fixes Run as Administrator : Right-click the Dolphin executable and select Run as administrator to bypass standard permission blocks. Add an Antivirus Exclusion : Go to your antivirus settings (e.g., Windows Security ) and add the Dolphin installation folder and the Dolphin Emulator to the exclusions list. Check Folder Attributes : Right-click your Dolphin folder, select Properties , and ensure the box is unchecked. Apply this to all subfolders. Use Portable Mode : Create a blank text file named portable.txt in the same folder as your Dolphin.exe dolphin iosfs failed to write new fst
Right-click the Dolphin.exe file and select Run as Administrator . If this fixes the issue, your user profile lacks proper writing privileges in that directory. 2. Free Up Disk Space
Many antivirus programs, including Windows Defender , block Dolphin from making changes to the fst.bin file because they perceive constant read/write actions as suspicious. Short-term mitigations Ensure Dolphin has been granted full
Right-click the ISO file > Properties > Uncheck Read-only > Apply .
If Dolphin doesn't have the correct permissions to write files in its own folder, the operation will be denied. This can happen if: Add an Antivirus Exclusion : Go to your
The error “iosfs failed to write new fst” is rarely a random glitch. It usually points to one of the following underlying problems: