Is butternut squash with veins OK to eat?
I know this is old but figured if you come across this again.
Squash generally last about one month after they are harvested. If the inner flesh contains any dark or mushy spots, discard it immediately.
I have had some white veins in my squash but they were just harvested and it tasted just fine.  Being that they are at 2 months old I would not risk it.