I have been using Lightroom 5 for a number of months now and just recently the ability to click from the thumbnails in the strip at the bottom to drag them into a collection has quit working. I have not been able to find anything online to help with this issue. I have tried rebooting my system, deleting some recently downloaded presets, etc. but can't figure it out. Please help. The work around to set a target collection and click on "B" to move selected image is a nuisance.