Reliquary-1.12.2-1.3.4.796
ProjectE-1.12.2-PE1.4.1
it's about what it considers to be invalid recipe
and that recipe I believe involves every item in the game.

could you share at least part of that log so that I can see a little bit more?

debug.zip

that spam seems to list every item in the game.

it's long enough to make it create three different logs. The middle one is literally only the spam.

hello?

First of all, most mod developers including me have real life outside of modding for Minecraft and in many cases we can't respond all the time so word of advice if you bombard developer like this it may very well happen they will just ignore you and close the issue.

Anyway I have no idea what ProjectE is reporting there as the recipe it complains about is just a completely standard shaped recipe where 5 glass panes make an empty potion vial. That is the recipe that's included in the mod, based on the ProjectE log that recipe was changed by something to include what seems like every item in your modpack. So the only thing I can advice is look for something that changes recipes or complain to ProjectE about that in case they are falsely reporting this as an issue. you can just point them to https://github.com/P3pp3rF1y/Reliquary/blob/1.12.x/src/main/resources/assets/xreliquary/recipes/items/potion_vial.json and they will see this definitely can't be causing that log spam.