Online playback not working properly

I have written a piece and need to send it to my choir to use for rehearsal tracks. The problem I'm finding is that the tracks stop half way through for no reason at all when they try and play them, same with me. I think some of them are doing it on phones or tablets if that makes a difference, have tried on a few scores I've uploaded and they all have the same problem. Anyone know what could be causing this? I've uploaded one as a sample but it's ahppening on all scores on online playback.