Dolphin Iosfs Failed To Write New Fst =link= Jun 2026

The most common cause is Windows Defender's , which prevents unauthorized apps from writing to the "Documents" folder where Dolphin typically stores data.

. This usually occurs because of insufficient file permissions, interference from security software, or issues with the location of the Wii NAND folder. Common Causes Antivirus Interference

the box next to Read-only (Only applies to files in folder) . dolphin iosfs failed to write new fst

The IOS_FS: Failed to rename temporary FST file error is typically a minor "handshake" issue between Dolphin and your operating system's security or file management software. For most people, the fix is simple: exclude Dolphin from your antivirus or cloud-sync folders.

Proposed solution (high level)

This can bypass permission restrictions but is often less effective than moving the folder. Right-click Dolphin.exe > Properties > Compatibility tab > Check "Run this program as an administrator" > Apply.

If your Documents folder is being synced by OneDrive, it can lock files while they are uploading, leading to write failures in Dolphin. The most common cause is Windows Defender's ,

Backward compatibility & safety

If your configuration data is stored on an external MicroSD card, try moving your primary game directories back to internal storage to resolve file writing roadblocks. Common Causes Antivirus Interference the box next to

Open your specific antivirus control dashboard (e.g., Avast, Malwarebytes, or Bitdefender). Navigate to the or Exceptions tab.

Navigate to the main directory where your Dolphin.exe file lives.