After finding chest in the cellar close to the mill, i can't open it. It's glowing red while using witcher senses, but i can't click on it. It's completely inactive, like it's not even there. I tried different angles but there is no "open" showing up. Is there a way to open this chest? I have 1.12 version

Did you find the note and the key? It won't open without them.

Yes. I got the key from dead guy near the bridge, and opened chest in a water there. Then i followed the quest to the cellar, and i'm stuck.

Sounds right.

You may have to go back to a save prior. Ensure you read the note you find so it is entered in your log.

I'm did read it the moment i got it. I still remember what whas written there and and quest changed to chest location after i read it. I also read that looting other chests my block it so i tried it 1 more time before posting here with the same result.

I got this. I reinstalled the game. Loaded last save and it worked. Maybe something went wrong when i patched the game before. Thank you Peetz for help.

Good stuff. It's always a good idea to ensure you are running the latest game and DLC versions. This game in particular, seems to very sensitive to that.

Just reading the change log for the upcoming 1.20 patch, there's a fix included:

"Fixes issue whereby treasure hunt titled Temerian Valuables could not be completed."

I have to say I've never come across it, but it obviously exists in some circumstances.

Still not fixed as of 1.24. I just started playing the Witcher 3 and about 10 hours in I come across this seemingly widely-reported and annoying bug. I suspect this is never going to get fixed and my quest log will never be complete. :(