GitFlow Branch Downloads Produce Internal Server Error (BB-7881)

We are using SourceTree as our client and we are using the GitFlow functionality to create feature and release branches. When we do this and we go to the BitBucket UI and navigate to Downloads for our repository and try to download the zip for different branches we get an internal error for some of the branches and not for others. Initial testing suggests that all branches with a forward slash in the name fail and all branches without a forward slash in the name succeed. Please see the attached document for examples.