I’m writing this down mainly so I can find it again when I inevitably forget how I fixed it (lol).

Transmit.app, the Mac file transfer app, started hanging whenever I tried to connect to my utility server over SFTP. Other servers worked fine, and I could connect to the utility server via SSH without any issues.

I ran a packet capture to see what was happening:

sudo tcpdump -s 0 -n -i en0 -w n.pcap tcp port 22 and ip host 192.168.xx.xx

I left it running while Transmit.app sat there trying to connect, then quit the app.

The capture showed a successful SSH connection, but it turned out to be my Terminal session. Transmit.app’s attempts weren’t making it onto the network. Meanwhile, the app was creating thousands of sockets and filling its own log with “Connecting…” followed by “Not connected.”

The macOS system logs explained why. A networking service called nehelper kept reporting:

Local network allowed by preference for Transmit (com.panic.Transmit), but received prompt. Clearing cached UUIDs and restarting session.

Transmit.app already had permission to access the local network, but macOS was stuck trying to handle that permission again.

I checked these logs through Terminal, but Console.app provides a way to watch them while reproducing the problem. To capture the same messages there, I followed these steps:

1. I opened Console.app from Applications → Utilities. It’s also available through Spotlight.
2. I selected my Mac under Devices in the sidebar and clicked Start to begin streaming logs.
3. I tried connecting in Transmit.app, then returned to Console.app.
4. I searched the message text for com.panic.Transmit or Local network, keeping All Messages selected.

I didn’t filter only for the Transmit process or messages marked as errors. The clue came from nehelper, and it wasn’t labeled as an error.

Once I knew where the problem was, I reset the permission:

1. I quit Transmit.app completely.
2. I opened System Settings → Privacy & Security → Local Network.
3. I turned Transmit.app’s permission off, then back on.
4. I relaunched Transmit.app and connected to the utility server again.

It connected successfully. I opened a remote folder and returned to my home directory to verify browsing worked. There was no new permission prompt, and I didn’t need to reboot.

The setting had said “on” the whole time. Turning it off and back on was what fixed it.