After sleep state, PC with Linux doesn't let me shut down the system

Question

I have been using Xubuntu as my main system for 3 weeks, but I noticed only today that after the pc has woken up from the Sleep state it doesn't let me shut down the system. I tried to shut down by using sudo shutdown now but what I get is

Failed to execute operation: There's already a shutdown or sleep operation in progress

There is another problem, as well, when the PC wakes form sleep it can't connect to the Network, I only use Ethernet connection, but it tells me that there is no connection available.
My PC works flawlessly until it goes in sleep state, I can't figure out what is causing my machine not to work when it wakes from sleep state.

Answer 1

I solved by changing my Nvidia drivers, it seems those proprietary drivers were causing the problem.