Panic apps “ssh key is not in a supported format” error

I recently started using Panic’s Coda as an alternative to Sublime Text, and it looks really slick – the inbuilt SFTP particularly could make a big difference to my workflow.

But I hit a snag pretty early – Coda wouldn’t accept my SSH key – neither would Transmit (a straight FTP app from Panic) – throwing a “ssh key is not in a supported format” error. Now they key definitely works – Terminal and Cyberduck were both fine with it.
There was nothing unusual about how the key was generated – it was under Yosemite in accordance with GitHub’s guidelines, and using a passphrase.

A quick search threw up quite a lot of similar problems, and plenty of different solutions – however none worked for me…

Luckily Panic give prompt support on Twitter and after a couple of suggestions found a solution that worked for me:

In fact I didn’t even need to use a ssh config file – but I have quite a simple setup at the moment. The important, and counterintuitive, part was to NOT select the key file, but enter the passphrase.
If that doesn’t work for you, and you’re getting SSH key errors in Coda or Transmit, there are a selection of other solutions in this thread.

9 thoughts on “Panic apps “ssh key is not in a supported format” error

  1. Thank you! Several programs in El Capitan are not honoring my ssh keys, although ssh itself still works flawlessly. At least your tip saved Transmit for me. Fixing my key for the other El Capitan apps is still up in the air.

  2. This finally worked. I was going bananas because my config file worked perfectly in Terminal! Thanks so much! You rock, kinda of annoying we still have to enter the pw, but all is well that ends well 🙂

  3. Updated to Sierra and suddenly Transmit had a dummy spit.
    Found this and followed thee tweets instructions, fixed it.
    Weirdly Transmit was functioning correctly in El Cap without it ¯\_(ツ)_/¯.

    Thanks Phil =) , from ~19 months after you posted this.

  4. Thank you! Since yesterday I had the same issue with Transmit under Sierra. Even though I am using Sierra since it’s release without any problems. Suddenly Transmit could not connect to my server any more…

    Your solution works fine!

  5. None of the suggested solutions out there solved my problem.
    The key was still in incorrect format (Transmit and Coda 2).

    I could connect to the server with the Terminal (in Coda).
    But not in by using the file browser.

    I found that Coda 2 could not actually access the key-file at all.

    My solutions was to allow Coda 2 to access my key file.
    I opened Keychain Access
    -> found my ssh key as a password in the list and opened it
    -> klicked on tab “Access Control”
    -> add “Coda 2”

    Now Coda 2 can access the id_rsa key and could connect to a server with the key.

  6. Thumbs up, five stars, yee-ha! This fixed my issue. Thanks a million! Happy to keep using Transmit, but disappointed that the fix for this issue was so obscure.

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