Did the map get updated at some point after it's release in which that happened? Seems the image that had that effect was named flashlight2.png instead of flashlight.png, the latter of which was what the script file was looking for. Somehow it was missing for many other people. the screen was darker due to a vignette effect.

If I may ask, what was that mode going to be like, and why did it end up being cut?

Hospice was going to have a Splenderman mode that would be unlocked if you collected 12 lines (equivalent to 6 pages) or more. Looking through the files and playing through the old FPSC versions of the maps in general, here are a few interesting details I've noticed.