Have been playing this great game for the past 2 weeks and loving it.

But recently (from 2-3 days), I have noticed a glitch/bug in the game where the enemies tend to not die even after their life line becomes zero! They go down on knees but then eventually stand up with full life again :S! Like at the moment I'm at the Ragged Flagon and have tried to kill the enemies but they just don't die. I'm sure it's a bug or something. Can anyone help?

Cheers

They're essential characters and can't die. Why are you attacking the people in the Ragged Flagon anyways?

Quest-critical characters are marked as "Essential" and can not die until they have fulfilled their purpose. Or some cases, they remain Essential. So people like Delvin and Vex are Essential.

I'm on the 'Cornered Rat' quest and in the Ratway to search for Esbern's hideout and there I am getting attacked so I have to defend. This has been happening before too like if I'm shooting down a dragon, the life line shows empty but it still is alive but dies after a few more blows!

Do you mean the Thalmor? Well, that's getting spoilery, but I dont know why this would happen.

Any fixes?

There's no fix on the consoles. Beth wanted to market to the casuals unfortunately

There is no fix for the non killable essential NPCs on consoles, there is on PCs however.

I know about the essentials, but what's with the dragon and sometimes other trolls, bandits etc? they tend to show zero life line but still not dead!