Taskbar in Win 8.1 Pro working and then stopped.Any icon in taskbar is inactive without any message or error.Even,in start icon I can not restart computer(right click/shutdown)

What`s goging on ?

If you're having problems with your PC, you can try to  refresh, reset, or restore it.

See:

How to  refresh, reset, or restore your PC

Hi Zoran,

When did the issue start to occur? Have you made any modifications to the machine?

We can try the following steps to have a troubleshoot:
1.Perform a clean boot to troubleshoot whether this issue is caused by a third party service.
How to perform a clean boot in Windows
https://support.microsoft.com/en-us/kb/929135
2.Create a new account and login with it to check whether this issue occured with the specific account.
3.Perform a full scan with the antivirus software.
4.Run "dism /online /cleanup-image /restorehealth" to check the health of the system files.
5.If the issue occurred recently, we can perform a system restore to revover the machine to a previous normal point.

Best regards