We're using Kerberos, and so the "/" is required to define the realm of our users.
However, when a user with a "/" in their username goes to create a personal space, they get a Confluence "page not found" page. For example, for a user name of "asdf/realm" would have this link to their personal space: https://bw-wiki.ncsa.uiuc.edu/display/~asdf/realm
If I manually point the browser to the correctly escaped link: "https://bw-wiki.ncsa.uiuc.edu/display/~asdf%2frealm" I get an apache "Not Found" error.
The link that is automatically generated by confluence is: https://bw-wiki.ncsa.uiuc.edu/display/~asdf%202frealm
Which is doubly escaping the "/", once to get to %2f, and then to %202f to escape the percent sign.
Please check where you're escaping your characters. Also, is it possible, even after proper escaping, to have a personal space for users with "/" in their usernames?