The application source tree can't be opened

[smXplorer]

Screen Shot 2016-01-13 at 19.38.09.png

This is the message I got when trying to start the app today (MacOS 10.11.2) - SourceTree autoupdating itself (recently selection option on my side).

I checked the Security preferences and the app doesn't appear flagged.

I would say that the last time I committed a repository was ~2 days ago.

What step can I take to resolve this problem?

[smXplorer · Accepted solution]

Rebooting the Mac fixed the problem...