Sector type 17 is disabled after loading a saved game

Sector type 17 is a lighting effect that was first introduced in Doom 2. The effect causes the lighting of the sector to flicker in random grades between its initial brightness and a value that depends on the neighboring sectors. Although the effect has been meant to work constantly, it becomes disabled if the player loads a saved game. When the restoration takes place, the sectors with the type will receive the light level they had at the moment the game was saved and flickering no longer occurs on them. The bug is still present in the 1.9. version of Ultimate Doom.