Why does Ubuntu 18.04.1 completely freeze when watching a video

I tried streaming a movie from online to VLC, the computer froze after a while. I tried playing a local movie in VLC, the computer froze after a while. I tried playing a local movie in SMPlayer, the computer after a while.

Every time the computer froze, the image froze and I couldn't do anything (couldn't switch to a any program, I tried a bunch of shortcuts such as Ctrl+Alt+F1)but the sound kept on playing.

The computer would freeze after a random amount of time, but the only way I could unfreeze it is by holding the power button until the computer shut down.

I even tried updating the repositories by doing sudo apt-get update/upgrade but it didn't do anything.

My computer: Ubuntu 18.04.1 with FDE R5 2500u 8GB DDR4 dual channel MX200 500GB SSD 1080p screen

I also had this laptop as dual boot Ubuntu and Windows for a while, without any issues. I did a fresh install to utilise full disk encryption.

If someone can provide me with help on how to solve this issue, it would be much appreciated.

Here is my VLC log:

-- logger module started --

main: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.

main: playlist is empty

-- logger module started --

main: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.

main: playlist is empty

glconv_vaapi_x11 error: vaInitialize: unknown libva error

-- logger module stopped --

-- logger module started --

main: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.

main: playlist is empty

glconv_vaapi_x11 error: vaInitialize: unknown libva error

-- logger module stopped --

-- logger module started --

main: Running vlc with the default interface. Use 'cvlc' to use vlc without interface.

main: playlist is empty

glconv_vaapi_x11 error: vaInitialize: unknown libva error

Solution 1:

I encountered several of these freezes recently on a laptop (trackpad). I used to think that the only way I could unfreeze it was by holding the power button until the computer shut down.

However, when I connect a USB mouse, the laptop unfreezes. Perhaps more of a workaround than a solution, but I suppose it is more practical than shutting down every time the computer freezes.