At my Shield's first trip to the range, my girlfriend had this issue with it. Hands me the gun, sure enough, slide is completely immobile and locked back all the way. Eventually I did just give the slide a hard smack to get it to return forward. I took it to the range again the next week and all was well! Before my first range visit I admit I didn't thoroughly clean the pistol. It came 100% dry from the store so I simply oiled it. Of course I did clean it thoroughly before that 2nd range trip, so perhaps that made all the difference. I'll update my post if I have the problem again.