It is a codec issue you can try and find the codec that your missing which is more trouble than it is worth.
Or you can watch it with VLC which will play dang near everything < it has all codecs built in.
Or like Repdaddy said pause or stop the stream let it fully load then try playing.
Sometimes you can pause/stop the stream then right click the player and turn off the audio track then back on and it will play.
If you want to try the codec fix just search for codec packs = There are a lot out there and I have tried most all of them.(K-Lite) is one of them ,but there is always the random file that doesn't play correctly...So VLC was the simplest fix for me...here is a how to stream/watch while downloading viewtopic.php?f=35&t=13460
When you install VLC either un-tick/(don't install) the plug-in or, disable the plug-in after you install under your browser extensions.
The VLC plug-in will prevent the IQS divx player from working.
Here is a post on that viewtopic.php?f=24&t=67384