I don't have background information, sorry.

Did you repot it before?

I think it might be one or a combination of the three:

• Not enough light: some leafes look unusually light or dark, and the whole plant is a bit droopy. Is it somewhere near enough a window? Still, not my top guess.
• Overfertilization: do you see the burnt tips, very dark-green leafes, and claw-shape? Especially the top leafes look like that.
• Oxygen deficiency (root rot): most likely. You have to act FAST NOW. Just not watering won't help. If you already see signs of it, and they are strong, the roots are already mush.

I would recommend:

• Check if the pot has drainage and the soil is light enough to store oxygen (e.g. by having perlite in it).
• Put it out and let it drip off.
• Don't water too much in the winter. Keep the soil slightly moist and let the top layer dry off sometimes.
• Consider semi-hydro with clayballs. You can't overwater, and if you still get root rot, you can act WAY faster (flushing, drying, etc.).
• And maybe add beneficial microbes, which will make the plant more resistant to root rot.

I think you will definitely get my reason why semi-hydro is great. In a few days, you'll get swarmed by fungus gnats. I haven't seen one since I switched to LECA ;)