Sorry to hear you are experiencing this issue in game, if possible could you confirm whether you are launching this through our launcher or another 3rd party app, also if you are running the standard version or through Vulkan.? In the meantime could I ask that you have attempted our basic troubleshooting steps as outlined here.
Got the same issue.
Basic troubleshooting steps didn't help.
I launch game using Ubisoft Connect or direct shortcuts.
When I start Vulkan version, game shows "Optimizing shaders (0%)", hangs and takes 25% of CPU (I got 4 cores w/o HT).
When I start standard version, game shows nothing but also hangs and takes 25% of CPU.
The issue started yesterday about 8 p.m. UTC +3:00.
Sometimes game crashes instead of hang (Ubisoft Connect show crash window and suggest to send report (some reports have been sent)). When the game crashes, it do it every launch until reboot.
Win 7x64, Core i5-4440, 16 GB RAM, RX 580 4 GB.