ArgumentException on pull and push (may be related to Askpass.exe)

When I try to push or pull I get the following message:
 

git -c diff.mnemonicprefix=false -c core.quotepath=false --no-optional-locks push -v --tags origin my-branch:my-branch
fatal: ArgumentException encountered.
An item with the same key has already been added.
error: cannot spawn C:\Users\my-username\AppData\Local\SourceTree\app-3.0.6\tools\Askpass.exe: No error

I have the latest version, 3.0.6, but I cannot choose it here.