every time i try to transfer pic to lightroom i get
The file is not recognized by the raw format support in Lightroom. (1)
DSC_0570.NEF, how can fix this?
The nikon D750 is not yet supported by Lightroom as it came out after the last update to Lightroom. You should transfer the pics manually to your hard disk first. Then use DNG converter 7.5 (free on the Adobe labs website - Adobe Photoshop Camera Raw 8.7 Release Candidate | digital camera raw file support - Adobe Labs) to convert the files to dng and import those into Lightroom. Those will work in LR 5.6 and earlier.