Let me start by saying your lightroom course is awesome so far! I am in section 4 working with catalogs and have hit a bit of a road block. I am running LRC with windows ten and for some reason an unable to drag and drop photos into collections. I googled the issue and even tried resetting LR Preferences. No luck I can select photos and right click on the collection to add them but it seems like it would be much easier to just drag and drop like in your videos. Any suggestions?