I'm currently playing Sevtech Ages of the Sky, and after unlocking blood magic I noticed that when I look in Sanguine Scientiem there are no images. There should be numerous images show how to setup the altar, etc. But mine only has text. I'm using a default mod pack with no additional modifications. GUI scaling, and other video settings don't fix it.

Oh, I'm sorry, I didn't realise you were on 1.12. I'm not sure about this bug, but I'm afraid that 1.12 is no longer supported.
As far as guidance goes, I can direct you towards this guide:
https://docs.google.com/document/d/1XLX9VgXOBSRBPyEptMprAJh_SE3W-zvXFGfDu-0m60Q/edit?usp=sharing

Hi - just to check, what version of Blood Magic and Patchouli are in your modpack?

Also, could we get a screenshot of the pages where there should be images?

Hey, Thanks for following up so soon.

Blood Magic: Alchemical Wizardry
1.12.2-2.4.1-103

[Edit: Guide-API-1.12-2.1.8-63 is installed in this version]
I don't see anything by the name of "Patchouli" in this modpack. However there are a couple 'patch' mods:
RandomPatches
1.12.2-1.22.0.0

SevPatches
1.6

A couple screenshots.

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Check to see if there's an update to GuideAPI. Haven't seen that bug before.