It's been a couple of days since I used Elementary OS and it worked as smooth as possible but then all of a sudden I started having this problem. Whenever I restart or shutdown my notebook, it keeps getting stuck in here where it says:
*Starting LightDM Display Manager *Stopping Send an event to indicate plymouth is up [17370.126206] [drm:intel_set_cpu_fifo_underrun_reporting [i915]] *ERROR* uncleared fifo underrun on pipe A [17370.126267] [drm:intel_cpu_underrun_irq_handler [i915]] *ERROR* CPU pipe A FIFO underrun
Here's a picture of the problem:
Thank you for helping me out.