The Urt5 Official Mapping plugin
This guide explains the steps required to install the FrozenSand - Urban Terror Mapping Plugin, and configure the Unreal Engine, to facilitate the creation of custom levels (maps) for Urban Terror 5: Resurgence.
Be aware that the Engine takes a lot of disk space (G0 GB+), and maybe 5 to 10 GB for a Level.
(This guide is for Windows. Some steps will vary on Linux.)