I was messing around with red stringed containers (trying to get them to link to the central block of an IE Arc Furnace). I had placed at least a dozen of them around it trying to get it to work, but to no avail. When i tried to break one, the screen went a grey colour with some weird text in the centre, and then the game promptly crashed. This bug happens whether the red stringed containers are linked or not, but I am not sure if it affects other red stringed blocks - it also did not affect at least one of the red stringed containers I broke for an unknown reason.
Crash Log:
https://pastebin.com/ub9b701F

I can reproduce this with all red string blocks (not just the red string container), and with just Botaniaand itemscroller. Crash log is the same as yours: https://paste.ee/p/gYyZc

I tend to crash slightly less often when I remove a red string block that is bound to something but it's not consistent.

Btw, i believe the "weird text" you mention is the game trying and failing to draw a "Shutting down internal server..." message. Possibly due to the GL state being all wacky, because the crash is in the middle of the red string spiral effect rendering method.

Was running this with only Botania on 1.12, could not duplicate.