Literally Stuck... Prompt doesn't show up for me to put the flasks in RE 8

[D@rk Knightz]

I already put 3 flasks in the alter early on in the game and I have a last flask so when I went to put in the alter. i can't place the last one and usually it would say press F but I don't see that either.

[DragonFire-SW]

for me now to.
2/4 are in and cant put the other 2 in :/