Songs stop randomly and "GStreamer error: negotiation problem" pops up.

[ShadyMedic]

Hi.

So I've downloaded Clementine a few days ago and I'm really satisfied with it, the only problem I observe sometimes is, that randomly in the middle of a song, it stops and Clementine jumps to the next song in my playlist. At the same time, a warning popup saying

⚠ GStreamer error: negotiation problem.
[Close]

appears.

I'm playing songs from my hard drive. They're in a folder that is being synchronised to ownCloud. Do you think that this might be the reason why the songs randomly stop?

Thanks in advice for your suggestions on how to fix this.

[ShadyMedic]

Edit: After pausing synchronization of that folder, the songs keep stopping randomly.