The Dolphin folder may be set to "Read-Only," or the user may lack administrative rights to modify files in that directory.
Select . If this stops the error, you can permanently set this by right-clicking the file, going to Properties > Compatibility , and checking Run this program as an administrator . 3. Relocate the User Folder
The "FST" refers to the , which Dolphin uses to track metadata and access control lists for content stored on the virtual Wii NAND. When Dolphin cannot write this file, it fails to update your virtual console’s internal memory, leading to lost saves or persistent error popups. Common Causes dolphin ios-fs failed to write new fst
Scroll to and click Manage Controlled folder access .
Many security suites, including Windows Defender, use a feature called "Controlled Folder Access" that blocks unknown applications from writing to the "Documents" folder where Dolphin defaults its data. The Dolphin folder may be set to "Read-Only,"
If you are running Dolphin in "Portable Mode" (with a portable.txt file in the folder), the emulator may struggle if placed in a protected directory like C:\Program Files . How to Fix the "Failed to Write New FST" Error 1. Configure Windows Defender / Antivirus
If OneDrive or folder permissions continue to cause issues, you can move the user data folder out of "Documents". Common Causes Scroll to and click Manage Controlled
The most common solution is to allow Dolphin through your security software.
Sometimes the emulator simply lacks the necessary permissions to write to its own folder. Right-click your Dolphin.exe file.
Go to .