Symptom → cause → fix. If your case is not here, check the session log (%LOCALAPPDATA%\SimpleZipDrive\Temp\Logs\debug_*.log) — it names the exact failing step — and see Logging.
x64/x86 Dokan on an ARM64 system (architecture mismatch)
Install the ARM64 Dokan build, or use the Dokan x64 package on x64 Windows
“Dokan error: …”, retries “attempt 1/2”
Transient driver failure
Usually resolves on retry; if persistent, reinstall Dokan
“Dokan Driver Outdated” — installed version below 2.3.0
dokan2.dll older than 2.3.0; DokanNet 2.3 needs the DokanRegisterWaitForFileSystemClosed export (older drivers crash the app instead of failing cleanly)
Update Dokan (releases); any 2.3.0+ or 2.x newer release works
“WinFsp driver service is not running. Please start the WinFsp.Launcher service.”
WinFsp.Launcher service stopped
sc start WinFsp.Launcher (admin) or restart via services.msc
“WinFsp version mismatch: installed x.y, required 2.1. Mount blocked.”
WinFsp older than 2.1, or interop/driver mismatch
Upgrade WinFsp to ≥ 2.1 stable. 2.2.x betas are fine
“WinFsp native DLL could not be loaded”
Native driver DLL unreadable
Reinstall WinFsp; check that no AV quarantined winfsp-x64.dll
“Missing Application File” — winfsp-msil.dll not found beside the exe
The interop library was removed (typically by antivirus) or the package was extracted incompletely
Restore winfsp-msil.dll next to the executable: re-download the complete package, extract all files into the same folder, and add an AV exclusion for the file if it keeps disappearing
/dev/fuse not accessible (containers, WSL1) or the mount folder is not empty
Ensure /dev/fuse exists and is readable; use an empty mount folder
FUSE session does not exit / “the drive may still be mounted”
The session is wedged or fusermount3/umount failed
Unmount from the system (fusermount3 -u <folder> / umount <folder>) or close the app; the mount is not reported as unmounted until the session actually exits
Mount-point problems
Symptom / message
Cause
Fix
“The mount point is already in use…” / 0xC0000035 + “Mount Point In Use” dialog
Letter or folder claimed by another drive/process
Pick a different letter/folder; subst-mappings and other virtual drives count
“Skipping ‘M:' (already in use).” for all letters
M–Q all taken
Mount to a folder, or free a letter
“Error: Failed to auto-mount on any preferred drive letters.”
Same
Same
0xC0000034“The WinFsp driver was not found or is not running” on a folder mount in versions < 2.9.0
Historical bug: folder paths were misclassified as drive letters, so the folder was never created
Upgrade to 2.9.0+ (fixed)
0xC000003A“The mount point path was not found”
Folder path invalid
Check the path
0xC0000022“Access denied”
Permissions on the folder
Choose a folder you can write to
“The path is empty” on every WinFsp mount in versions < 2.9.0
WinFsp interop crashed inside the single-file bundle (Assembly.Location empty)
Upgrade to 2.9.0+ — winfsp-msil.dll now ships beside the exe
Archive problems
Symptom / message
Cause
Fix
“The file ‘X’ is not a supported archive”
Extension not in the supported list
Rename to the correct extension if it is a supported format; otherwise convert
“The file is not a valid Xbox XISO disc image (.iso, .xiso, or .cso)”
The file is not an Xbox XDVDFS image — e.g. a PC data-disc ISO, a DVD/Blu-ray image, or a renamed file
Only original Xbox and Xbox 360 game images are supported (this is not a corruption error). See Archive Support
“Archive file not found at ‘…’”
Path wrong / network share unreachable
Check the path
Password dialog loops, then “Mount aborted after 3 attempts”
Wrong password
Verify the password; cancelling stops the mount cleanly
“The archive file appears to be corrupted, incomplete, or uses an unsupported format/feature”
Broken download / unsupported feature
Re-download; test the archive in 7-Zip; note that corrupt RARs are reported as corruption (not as password prompts) since 2.9.0
Specific entries unreadable, log shows “Decompression failed” / “SevenZip fallback also failed”
Entry-level corruption or exotic compression
Verify the archive; re-create it if possible. If the log says the fallback is unavailable, check that 7za.exe/7zzs/7zz and 7zip-license.txt are present beside the executable and that the binary is executable on Linux/macOS (chmod +x)
“Insufficient disk space to extract file ‘…’”
Temp volume full
Free space on the drive holding %LOCALAPPDATA%
Runtime behaviour
Symptom
Explanation
Action
“A drive is already mounted. Please unmount it first.”
One mount per instance
Unmount, then mount again
Memory appears to “double” the file size in Task Manager (versions < 2.9.0)
Transient double-buffer during decompression
Upgrade to 2.9.0+; also see Caching for the new single-buffer path
High RAM after opening a huge file
Entry cached in memory up to MaxMemoryPerFileMb
Lower the setting to offload big files to the disk cache
Leftover Temp\<pid>_<guid> folders after a crash
Session died before cleanup
Auto-swept at next startup, or use Clean Temp Files
Empty folders in %LOCALAPPDATA%\SimpleZipDrive\Mounts
Cross-integrity mount points are not auto-deleted
Remove manually when unmounted
Update check never appears
Silent when offline, or you are already current
Check the log line “Update check skipped: …”
App closes instantly on unmount of large drives
Watchdog force-exit if cleanup exceeds ~5 s
Data is safe; temp files are swept next startup
Clean reset
Close the app (unmount first).
Delete %LOCALAPPDATA%\SimpleZipDrive.
If mount points stay broken, restart your system (driver state resets).
Still broken? Reinstall the driver (Dokan/WinFsp) and the app (Installation).