According to the release notes, the new Radeon Software Crimson Edition brings support and optimizations for the new DirectX 12 mode in Deus Ex: Mankind Divided as well as a new AMD Crossfire profile for DOTA 2 in DirectX 11.
There are a couple of fixed problems, including flickering seen with 144Hz non-FreeSync displays, some bugs in games and applications like DirT Rally, Grand Theft Auto V, Doom, Total War: Warhammer, SteamVR benchmark and others. It also fixes problems with Radeon Settings and Radeon Software on some AMD Crossfire configurations as well as an issue where RX 400 series graphics cards experience high GPU usage when resuming from sleep.
As always, the new Radeon Software Crimson Edition 16.9.1 drivers are available for Windows 7, Windows 8.1 and Windows 10 OS in both 32-bit and 64-bit versions and support all AMD graphics cards since the days of the HD 7700/HD 7900.
You can download the latest Radeon Software Crimson Edition 16.9.1 drivers over at AMD's support page.