Can you give me a little more information about where you're seeing this? Are you editing files from the website? Are you committing locally and pushing to the site? Anything you could tell us will help.
We have been having some site issues lately, so that is likely the cause of this. You can monitor the situation at http://status.bitbucket.org. We are working hard to have these problems resolved as soon as we can.
I'm trying to make changes via the website, then pull via SSH. However, I can't make any commits whatsoever on any directory. No errors. Just a message saying "We had trouble committing your changes.". I wish I could give more info but that's all there is.
I was just able to change a file online without any errors. Have you tried again recently? If it's still failing for you, can you let me know which repository (or repositories) you're having trouble with? If you'd rather not post them here, you can email email@example.com and we can help you there.
We've had some cases recently where git is not correctly releasing locks on certain branches, which I believe was the case here. I removed the lock for that repository, so you should be able to commit now. Let me know if you're seeing any other problems.