OTHER in my WD ex2 Ultra taking far too much room!

I use WD sync and as we all know it creates a sort of mirror that eats precious memory (mine stands at 41GB at the moment!). I ended up using GoodSync for a while as it allowed me to get rid of this problem but in the last ten days GoodSync is not working and all attmepts to configure etc on Mycloud control panel itself throws me error messages. SO back with WD sync which works well but is there a way to free this space at all please? any suggestion (smple is best for me lol) welcome!