Hi , I have had this happen once before, now before you try this, I hope all our photos are backed up to an external hard drive, if not do not attempt this. I could not down load photos, it was the phone/camera problem, I switched off, then open the phone, take out the battery, wait a few seconds then replace the battery, clip phone together again. Switch the phone on, reboot, and then try to down load again.
Please consider a second opinion before tying this.
