visual studio waiting for a required operation to complete

Hi,

I don't know if this is the right topic, but lately I often encounter this problem "visual studio waiting for a required operation to complete".

I get a pop-up box saying if I encounter this problem frequently, I should contact microsoft. So I did, but I don't know to what topic this problem belongs. (I'm using MS VS 2013 ultimate). 

Does anyone know how I can fix this?

Thanks ;)