There are a few features not working in Creator Studio. The fix is complete and is waiting for the Chrome store to review and publish the change. 

In the past, the review has been done in hours. Now it takes a week. Unfortunately, there is nothing we can do but wait for them to review and publish the change. Sorry for the inconvenience.

If you are trying to use TubeBuddy on the My Videos page of Creator Studio, there is a workaround. You can hover over the video, click on the details icon and then click on the TubeBuddy icon (see video below).