As not logged in User i get the following message when trying to visit any repository site or the site https://bitbucket.org/site/master/issues:

500
Something went wrong.
You can contact support or create a public issue if the problem persists.
This might be useful in debugging the problem:
659ffbebc5d14446a70669e6d4aa0ada

Tested on Firefox and Chrome, OS is Windows 8 64 Bit