Universal Media Server | Forum

Unfortunately that is one of the downsides of transcoding. the file is being converted in real-time and sent straight out over the network, but there is no way of knowing what the total size of the file will be to work out how long the file is. Some renderers can handle that properly but some like the webplayer can't

I like to think of it as watching a livestream, you can't jump forward if it hasn't happened. and as the player thinks it is a normal file it is not keeping what it has already played in memory there is nothing to rewind to either.

Watching on your TV or console is less of a problem as I'm guessing those are being streamed and the renderer is handling the displaying the subs.

Not sure. Its not something I use but maybe windows media player can, there is a config for it but don't know how to set it up. VLC should do the job but I have no experience with it.

VLC works kind of half-good. Kodi on the other hand works very well. I haven't tested the later versions of Kodi, since when v17 came out a lot was broken in the UPnP/DLNA support. So, I'm still using Kodi 16.1, which works very well as a "renderer" except for watching still images - but that's not that big a deal for me.