Hyper-v in Windows 8.1 Pro - why can't I activate Hyper-v Platform?

Question

Virtualization

On Windows 8.1 Pro, I want to activate the Hyper-v platform. When I select Hyper-v to activate from the Windows Features menu, after applying all the changes, a reboot occurs, after which the computer cannot turn on. Everything gets stuck at the stage when the Windows 8 logo appears and the circle with dots spins endlessly.
If you activate Hyper-V Management Tools - there are no problems, but if you choose Platform - then it's a disaster.
In the BIOS, the virtualization function is enabled, the processor (i5-3210M) also supports virtualization. Yes, and VMware Workstation works quite smoothly and without problems. But I also want to try Hyper-V.
How can the problem be solved?