Are you Dragging the Folder to Library Module or in the Import Window?
Click on Import in Library Module and then drap and drop the Folder you want to import
Also Which version of Lightroom are you using ?
i use the latest Lightroom CC 2015 update,
how i said, previously, i did drag them directly into the library module and it worked now it does'nt
If resetting preferences doesn't work: Are you on Windows? If so, are you running LR as Administrator?
Yeah running Lightroom cc as administrator was the problem, thanks for helping me figuring that out
Windows restricts the ability of windows running as administrator to interact with windows not running as administrator. I don't know all of the restrictions, but I've observed it in the past many times.