Diff fails to load on pull request page when target branch doesn't exist yet

Diff fails to load on pull request page when target branch doesn't exist yet.

Example Pull Request:
https://bitbucket.org/wfmdigitalweb/wfmcom/pull-request/853/qd-1337-added-google-button-to-blog-page/diff

A branch wfmcom/QD-1337 doesnt exist yet so because of this bug it's diff doesn't load for this Pull request. Instead it throws an error (also see screenshot):

#!quote

Error
We were unable to load this page.

Merging topic branches this way is our main git-flow approach and it used to work just fine before last week.

Currently this error happens(1) every(2) time(3) when target branch does not exist which almost blocks our ability to review Pull requests on the project.

We are a remote team and it's very hard to go to the parent team and ask them to create a copy of master branch in target repo and name it as target branch only so diff would display. This kills the whole automation idea.

Please pay attention to this issue!