Same here on Alienware 13 with graphics amp w/RX 480.
Tried DDU/AMDCleanup multiple times and still don't get relive.
Relive is currently only supported on Discrete Desktop GPU's
Taken from the Release notes Radeon Software Crimson ReLive Edition 16.12.1 Release Notes
Compatible with desktop discrete AMD Radeon™ GCN and Radeon RX 400 Series enabled products with at least 2GB of VRAM, AMD VCE Support and Windows® 7/8.1/10 64 bit operating systems. Radeon ReLive is currently considered "as-is" beta level support for 32 bit operating systems.
Totally understood, but still missing on my 8GB RX 480. sorry for hijacking this thread!