A Minor but Recurring Issue: IOS_FS: Failed to rename temporary FST File

[StrangeguyStrangeperson]

Environment Information

• CPU: Intel Core i7-14700K
• GPU: Nvidia RTX 4070 Ti SUPER
• OS: Windows 11 Professional

Version

• RetroArch: 1.17.0
• Video Driver: Vulkan (Others have also been tested to the same result)
• Core: Dolphin (dolphin-emu 2f4b0f7)

In the following version of RetroArch and its available Dolphin core, and with the above Windows 11 environment, loading any GameCube or Wii game throws up an error box stating, "IOS_FS: Failed to rename temporary FST file". This error notice will usually repeat 1-2 more times after pressing OK, after which the game loads and runs as per normal. Subsequent GameCube or Wii content loaded during the same session of RetroArch will boot without this issue, even after switching to a different core and loading content for it. However, the error will happen again for the first GameCube or Wii game loaded in a new session. This is particularly bothersome (if ultimately not fatal) for things like LaunchBox integration, since by default LaunchBox starts a new RetroArch session each time content is prompted to load through it.

I have begun verbose logging of RetroArch to help identify the inner workings of the error. The full contents of the log are available via
this link.

In particular, I would direct your attention to this recurring error notification:

[libretro ERROR] 14:19:372 Common\FileUtil.cpp:285 E[COMMON]: Rename: MoveFile failed on C:\Games\RetroArch-Win64\saves\dolphin-emu\User\Wii\fst.bin.xxx --> C:\Games\RetroArch-Win64\saves\dolphin-emu/User/Wii/fst.bin: Unable to remove the file to be replaced.

I will note that both files mentioned are set to full read/write access. As well, controlled folder access is disabled (as Windows Live Protection is also disabled). and RetroArch is not being run as an administrator (though running it as an administrator has no effect on replicating the error). I have also tested loading a game with antivirus disabled, with no effect.

All core settings have been tested in their default state, and all RetroArch directories are default relative to the installation location (which is a simple C:\Games\RetroArch-Win64 pathing, i.e. not in Program Files). RetoArch was installed via setup application (so not an extracted/portable installation), and uninstalling and reinstalling both RetroArch and the Dolphin core have not changed the behavior.

My attempts to find information about this error online suggest this is a recurring issue with both the Dolphin core and some versions of the standalone emulator (though my current installation of the standalone emulator does not have this issue). Nothing I've tried in those disparate forum posts across the internet has had any effect. I'm therefore submitting my experiences with the error as an issue, in hopes that describing it and providing supporting documentation to the best of my ability will help point the way towards a definitive understanding of the problem.