Commander One not working: what to check, in order

Most attempts to fix Commander One start with a reinstall, and most of them do not help. Read through the vendor's own support material and a pattern shows up: the symptoms people report are almost never defects in the app. They sit in one of four layers, which are macOS permissions, which build got installed, how the connected device is configured, and licence activation. Checking those four in order takes a few minutes and removes the guesswork.

Layer one, permissions, because macOS 10.15 changed the rules

External drives missing, network drives never appearing, certain folders throwing errors on open. This family of symptoms is almost always Full Disk Access not being granted.

From macOS 10.15 onward, Apple tightened what third party apps may read. A file manager runs straight into that by design, because its entire job is reading everywhere the user can reach. The vendor's guidance is direct: granting Full Disk Access is the way to make the app behave correctly.

The path is System Settings, then Privacy and Security, then Full Disk Access, and apps are added by dragging them in from the Applications folder. On anything older than macOS 13, the lock icon in the lower left has to be clicked and the system password entered before the list can be edited. The app can also raise its own request window to do the same thing.

One detail worth knowing: the change often does not take effect until the app is relaunched. A list that looks unchanged immediately after granting access is not evidence the fix failed.

Layer two, which build is installed

Symptoms of the form "the menu item is not there" are not defects at all. They are the build.

The Mac App Store version cannot offer seven things, because Apple's sandbox does not permit them: the command line, the terminal emulator, quitting processes, mounting iOS devices, restarting as root, ignoring the system settings for F1 to F12, and ejecting local drives. The vendor states plainly that the App Store version and the PRO version from its site are different products with different feature sets.

The second split inside this layer is free versus PRO Pack. FTP and SFTP, Amazon S3, Dropbox, Google Drive, OneDrive, mounting MTP and iOS devices, and the built in terminal all live on the PRO side. Running the free build and finding no way to add a server is expected behaviour, not a fault. Before troubleshooting anything else, confirm which of the four builds is actually running, because two of the four cannot produce the feature being looked for under any configuration. The Features page is a useful reference for which capability belongs where.

Layer three, the device, when Android or a camera will not appear

An MTP device missing from the drive list is usually caused by the device side or by another app on the Mac. There are several things to rule out, so work down the list:

• Whether the USB cable supports data and is not a charge only cable
• Whether the MTP Devices extension is enabled in the app's preferences
• Whether MTP was switched on at the device end after plugging it in
• Whether USB debugging is enabled under the developer options, which the vendor lists as mandatory for Samsung phones running Android 7
• Whether another MTP using app is installed, such as Android File Transfer, Samsung Kies or Samsung Smart Switch
• Whether Photos, iPhoto or Image Capture is launching automatically on connection
• Whether Google Backup and Sync, formerly Google Drive, has its USB device option enabled

The reason the list is long is the protocol. MTP gives exclusive access to whichever app claims the device first, so a rival transfer tool sitting in the background is enough to make the device invisible. The app raises a notification when it detects one. Removing Samsung Smart Switch has its own procedure: download the installer, mount the disk image, run Uninstall.app, then restart the Mac.

There is one more behaviour that catches people out. Cancelling a copy to or from a mounted MTP device makes that device unusable for the rest of the session. Relaunching the app does not recover it. The cable has to be physically unplugged and reconnected.

Layer four, the function keys, which are a permissions problem wearing a disguise

Dual pane file managers inherit a tradition of mapping copy and move onto F5 and F6. On a Mac those keys belong to brightness and volume by default, so the app's whole keyboard layer can look dead.

The fix runs in two stages. First, turn on the option to ignore system settings for F1 to F12 and restart the app. That produces a warning with a button leading to System Settings, then Privacy and Security, then Accessibility, where the app has to be found in the list and enabled. On macOS 12 and earlier, the lock icon and a password come first.

Keys that used to work and then stopped need the reverse order. Remove the app from the Accessibility list with the minus button, restart it, then run the two stages above again. The registration is being rebuilt rather than repaired, which is why a straight re-toggle usually does nothing. This tends to surface after a macOS update.

On the App Store build, the option to ignore the system settings for those keys does not exist at all. Hunting for it there is a layer two problem, not a layer four one.

When restart as root stops halfway

Restarting the app with administrator rights is documented as not always working correctly, with three workarounds given in order.

The first is to repeat the action, because the app sometimes quits without relaunching and a second attempt completes. The second is restarting the Mac. The third is launching it directly from a shell: open Terminal, run the executable inside the application bundle with sudo, and enter the administrator password.

If this feature is part of a daily routine, that routine is worth questioning. Operations genuinely requiring root come up a handful of times a year for most people, and one sudo line is faster than a relaunch cycle. A setup where folders, a shell and an assistant share one window removes the switch entirely, which is a different fix from making the feature work.

When it is simply slow

Slowness is neither a permissions nor a build problem, and the release history is the fastest way to place it.

Three fixes are recent enough to matter. Lagging and hanging after drag and drop operations on macOS 26 was fixed in 3.17, alongside Quick Look preview on the same OS. Performance in folders containing very large numbers of files was improved in 3.11. Memory use when extracting RAR archives was improved in 3.16.

If the slowness matches one of those three, updating comes before changing any setting. App Store releases trail the site version by days or weeks because of review, so a fix that already shipped on the site may not have arrived yet.

If the current version behaves the same way, narrow it to two variables: how many items are in the folder open in each pane, and how many remote connections are held open at once. Both cost time every time a listing is rebuilt. Disconnecting remote mounts one at a time identifies which route is carrying the weight.

Layer five, activation, and what happens on a Mac with no connection

Paid features switching themselves off, or an activation prompt appearing out of nowhere, comes from how licensing is verified.

Activation needs internet access, and the app re-verifies periodically in the background to keep the licence check current. On a Mac kept off the network, or one that has been offline for a long stretch, that is where it stalls. An offline path exists: export an activation info file from the app, carry it to a machine that is online, submit it on the vendor's activation page, and load the returned file back into the original Mac. The address used in that step still carries the vendor's former brand name, so follow the address shown on screen rather than assuming it is wrong.

The free build also activates in the background, but with no code to enter, and the vendor states it exists for statistics only. Being asked for an activation code while running the free build means the assumption about which build is installed is wrong, which sends the investigation back to layer two.

When an SFTP server refuses the connection

Remote connection failures deserve separating out, because the cause is usually on the server side and the error text rarely says so.

Three capabilities arrived through updates rather than being present from the start, which matters if the installed copy is old. Support for PPK key files, the format PuTTY generates, was added in 3.9, along with support for FIDO and FIDO2 compatible hardware keys. Connecting to SFTP servers protected by two factor authentication was improved twice, in 3.14 and again in 3.15. So a server that rejects the connection may simply be asking for something the installed version cannot present yet.

Before assuming a defect, check three things in order. Whether the key file is in a format the app reads, converting it if the server was set up from a Windows client. Whether the server requires a second factor, and whether the installed version is recent enough to handle it. Whether the same credentials connect from a plain command line client on the same Mac, which separates an app problem from a server or network problem in one step.

Reading a symptom back to its layer

Symptom	Layer	First thing to check
Drives not listed	Permissions	Is the app in Full Disk Access
Menu item absent	Build	App Store version, or still on free
Phone or camera absent	Device	Cable, extension, rival transfer app
Device dead after cancel	Device	Cable unplugged and reconnected
Function keys ignored	Permissions and build	Accessibility entry rebuilt
Restart as root stalls	Known issue	Retry, restart Mac, launch with sudo
Features switch off	Activation	Internet access, offline procedure
Slow or hanging	Build	Current version, folder size, open mounts
SFTP refuses to connect	Server side	Key format, second factor, version age

What to change first

Work down the layers rather than across the symptoms. Permissions, then build, then device, then keys, then activation, with slowness checked against the release notes before touching settings. Reinstalling belongs nowhere in that sequence, and the documented uninstall procedure is only dragging the app to the Trash and emptying it, which rebuilds almost nothing. If the cause turns out to be the number of windows rather than any one of these layers, Compared with other file managers and the questions collected at Atriens are the places to look next.