v1.9.4 fresh-install is totally unusable

When installing a fresh-copy of the most recent SourceTree(1.9.4) on OSX, can't get any windows/dialogs to display in order to create a repo.

Secondary windows/dialogs, such as Preferences, About, etc, do display.

Related: on another computer which was previously running an older version of SourceTree, upgrading to 1.9.4 did not present this problem

Workaround: installing 1.9.3 seems to be working
http://downloads.atlassian.com/software/sourcetree/SourceTree_1.9.3.dmg

Problem described in more detail here: https://answers.atlassian.com/questions/303097/sourcetree-opens-but-doesn-t-show-the-application-window