Until further notice, it is recommended against using Tor Browser’s Internal Updater for security reasons.
More information and how to securely update is documented in the wiki, see:
User support discussion:
Forum development discussion:
The Tor Project has fixed this in TBB version 4.5a3. (As per blog post.)
At time of writing, currently advertised stable version is 4.5.1, that should no longer be affected by this issue.