Error 'ssh-agent' failed with code -1: System.NullReferenceException

[Vittorio Sozzi]

Hi, I have the latest SourceTree for Windows (version 3.4.8) and using Git standalone version 2.35.1.windows.2. I am using Windows OpenSSH for authentication.

SourceTree gives the following error:

This happens:

• - every time SourceTree is opened
• - every time I close the Tools -> Options window
• - every time Tools -> Launch SSH agent... is clicked

Any idea on how to solve this?

PS: Here is my git configuration on SourceTree Options: 

Update (2022-06-01): this still happens with SourceTree version 3.4.9

Update (2022-10-19): this still happens with SourceTree version 3.4.10. This is frustrating! Time to change git GUI...

Update (2023-09-28): this still happens with SourceTree version 3.4.15.

[Niko Frenkenberger]

this worked for me:

(This solution is based on Dan Worleys answer on the thread
"SourceTree unusable on startup ('ssh-agent' failed with code -1: System.NullReferenceException)" in some Jira ticket I found online)
https://jira.atlassian.com/browse/SRCTREEWIN-8375

1. Uninstall SourceTree from `Add or remove programs`
2. Delete the following:
   • C:\Users\<UserName>\AppData\Local and delete SourceTree & SourceTree-Settings folder
   • C:\Users\<UserName>\AppData\Local\Atlassian and delete all SourceTree Files/Folder.
3. Reinstall SourceTree

Deleting all atlassian appdata files seems to help for multiple problems. I remember an error where I couldn't start up Sourcetree anymore. The splashscreen showed up and disappeared again without starting sourcetree itself. For that bug the solution was the same: delete all AppData files for sourcetree.

Hope this helps for any poor soul in the future trying to find a solution, cheers :)

[Gonzalo Piffaretti]

I have the same issue. Everything works as expected when using git in bash or powershell. Sourcetree is just not playing nicely with OpenSSH.
Also evaluating a change.

[Vittorio Sozzi]

I opened an issue in SourceTree for Windows Jira https://jira.atlassian.com/browse/SRCTREEWIN-14297

If you feel like it, you can vote/comment it.

I don't have much faith that it will be considered or even corrected but at least I reported it.

[Vittorio Sozzi]

this still happens with SourceTree version 3.4.10. This is frustrating! Time to change git GUI...