kdl 46we5 mkv doesn't play

I can't seem to play any mkv at all, I have serviio 1.3.1 profile set to 2009 bravia some movies have sound but most don't and the picture is either a completely garbled colours or a black screen with a green box down the bottom right hand corner. I am new to this so please bare with me I have tried to google the problem but there isn't anything in relation to it and there is a similar thread on the first page with no solution.

Edit: Just thought I would add that I have tried updating to the latest firmware listed in the sony bravia sticky but it says it isn't compatible with my tv yet clearly states in the description that it is.

[Illico]

I suppose that your TV is connected to your PC (serviio) with Wire or Wifi network and probably connected to your rooter too, isn't it ?
So your TV should update his firmware automatically, what is your TV firmware version ?

The tv is network connected via wifi bridge we currently have no real internet connection just wifi dongle and phone hotspot the firmware is currently pkg1.429aa (Australian Firmware?).

I have read the post a couple down from this about the 46w5500 with mkv playback issues and have got it to play mkv's just is very jerky with higher quality ones, seems to make the tv very unresponsive guessing from not enough processing power. I'm talking 15gb 1080p bluray rips in .mkv which from what i've read aren't really supported by this TV's dlna setup anyway, what would be the best way to remux/transcode these on the fly to save me having to manually transcode them?

[Illico]

That could be due to high video bitrate that your TV does not support (or network)...

Could you provide information about your mkv file (see signature link) ?

Could you check the video bitrate with this tools: Video Bitrate Viewer