Hmm this seems to be a common problem which is happening at the same time for people...
I've wiped the cache thing and used safe mode and still no change. Like you, I also would like to get photos off my phone before i factory reset it
this happened to me a few days ago...the guys at Samsung Help flashed my phone and still no change. I can't put it on safe mode either. They suggested doing a factory reset should do it...but i've got some photos from a recent trip and i'd love to get them off the phone (which is locked)...