You should be able to reset your phone on this build, do a restore from a backup, and have your apps installed and restored appropriately. (blogs.windows.com)
In fact, you can't install a custom ROM unless you previously hard reset your phone and clear cache from its internal memory. (android.gs)
Until then, according to some users, the only solution, if the problem persists, users can simply reset the phone to make it work. (ibtimes.com)