Just to clarify, this is not related to git not being able to push/pull from stash over https (I use http.sslNoVerify=false to fix that).
In sourcetree when I click "Clone/New" then click browse hosted projects (earth button) I get an SSL errror: "The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel."
I get this error because my network administrator enforces a rule to not trust any SSL certificates. With git I use the sslnoverify setting and in browsers I click through the SSL warning or turn it off alltogether on internal sites. Is there a way to get sourcetree to ignore SSL warnings when browsing hosted(stash) projects?