GSF Necromancy is supposed to add another die of damage to a Negative Energy Ray spell. Vipers Fang Symbol as well is supposed to add 1 more. Over the past few resets, this isn't working. Tested extensively.
As usual, details are important.
What character, what class, what possible spellschool do you have, etc. So we can check potential possibilities and issues.
From additional testing and further experimentation this sees to work as intended.