I must have received a bad batch of Night Sight brew because while the game is under the impression that I already have "night sight", my senses scream the contrary. I attempted to drink another bottle of the nasty black tincture with a notice that I am already under it's effects. I then attempted to enhance my perception by use of arcane words "In Lor" to which I received the same message. This test was conducted in Hythloth and Wrong.
Not sure if RP or bug report... I noticed this a while back too, then someone informed me of the filter on razor which forces night sight.
heh. yeah to clarify this is definitely a bug report. I'm aware of the Razor light filters, but I intentionally choose not to apply it sometimes. I was testing out a batch of 5 kegs of nightsight which brought this 'oversight' to my attention.
Night sight potions and spell seem to not function when Dark Nights is enabled, in several locations.