I'm wondering if someone can help me with this, I've tried to find help everywhere but I'm not finding anything.

During the last boss, after you use the umbilical cord, and go to pick up a spear I can't move. The spear isn't in my inventory, I can't press any buttons except for scrolling through my inventory. the actual spear is in my hand, Walter points his gun, but doesn't shoots at me, while Eileen continues walking. I can't even pause the game, my only options are to scroll through the inventory or alt-f4

Does anyone know what would have caused this and if there is a fix?

Thanks.

I haven't played this on PC, but... did the problem reoccur after restarting the computer and re-loading your last save? If so, then try loading a save from farther back, maybe.