HD movies won't play (8.1.1)

New to LibreELEC. I can't get it to play HD movies. I select it and it starts to play but I get a blank screen and no sound. The counter is moving so it should be playing. Also if I leave it playing and go out into the System settings menu (without changing anything) it will sometimes start sound and sometimes start video. SD movies seem to play mostly OK. I was running an older OpenELEC and everything was playing on it so I know the hardware is OK. Anyone got a fix? Thx.

Quote from Klojum

Sorry, our crystal ball is currently malfunctioning.

What are you using for playing HD movies on?

Asrock H81M-ITX

Intel Pentium G3258 Aniversary Unlocked dual core 3.2 GHz

Silverstone Sugo case

Kingston HyperX Fury Memory Black 4GB 4GB DDR3-1600

XFX ONE ATI Radeon HD 5450 SN: Q1Y085761

Kingston HyperX Fury 120GB SSD SATA

Quote from Jocke.Sve

Step 1: Provide Logfile!

log file

I initially set it up with PlexKodiConnect but when it wasn't working I tried without PKC and the issue is the same.

Can anyone help?

Figured it out. I made the assumption that newer versions of Kodi would work on the same hardware. Not so apparently. It will not play HD movies using the ATI Radeon HD 5450 video card. It will play them using the onboard video. Strange!