The BobLibrary mod is removing Rails from the Production Science Pack. Noticed my rail production was zero and everything seem to running fine. Rails are not required by the Production Science Pack Recipe. The only Mods I have installed are BobLibrary, BobLogistics, BobEquipment, BobPower, BobMining, and BobAssembly. No other mods. Something is causing the mod to modify the recipe.

5.797 Loading mod boblibrary 1.1.3 (data-final-fixes.lua)
5.798 Script @boblibrary/technology-functions.lua:996: Running technology prerequisite cleanup...
5.801 Script @boblibrary/recipe-functions.lua:697: Running recipe ingredients cleanup...
5.805 Script @boblibrary/item-functions.lua:102: stack traceback:
boblibrary/item-functions.lua:102: in function 'ingredient'
boblibrary/recipe-functions.lua:654: in function 'duplicate_ingredient_check'
boblibrary/recipe-functions.lua:679: in function 'duplicate_ingredient_check_full'
boblibrary/recipe-functions.lua:699: in function 'ingredients_cleanup'
boblibrary/data-final-fixes.lua:2: in main chunk
5.805 Script @boblibrary/error-functions.lua:88: Ingredient.name not a valid item of any type.
5.805 Script @boblibrary/recipe-functions.lua:665: Invalid item found on recipe production-science-pack.
5.820 Script @boblibrary/item-functions.lua:102: stack traceback:
boblibrary/item-functions.lua:102: in function 'ingredient'
boblibrary/recipe-functions.lua:654: in function 'duplicate_ingredient_check'
boblibrary/recipe-functions.lua:679: in function 'duplicate_ingredient_check_full'
boblibrary/recipe-functions.lua:699: in function 'ingredients_cleanup'
boblibrary/data-final-fixes.lua:2: in main chunk

The function you're quoting here is a safety check feature that was added due to certain combinations of mods causing loading errors.

it is on data-final-fixes, which means All recipes SHOULD be set up by then. Which means with this runs, anything that fails any of its checks will most likely error after this stage. It basically checks for 2 things.
1: Duplicate Ingredients (this is where the same item is listed on the recipe twice.)
2: Valid items. (It will also fail this check if the format is wrong)

The fact that in your error report the script is listing the item as "Ingredient.name" is concerning though. it makes me think there's an error in the script passing the string "ingredient.name" instead of the ingredients name.
what items are on your Production science pack?

I found the error.
Rail is a unique item type "rail-planner", which isn't on my valid item types checklist.
There has been a few new ones added to the game since I wrote the "Valid items" function, so I guess I need to update the list.

And I thought it was me. I removed everything but boblibrary and the rails are still removed from the Production Science pack. With BioIndustries mod it removes rails from the new Production Science pack recipe that mod adds.

I am at build 1.1.27, and tested this on a new game without any other mods. (Also tested again with just BioIndustries mod added in addition to boblibrary.)

For me, the original two items (electric-furnace and productivity-module) in the Production Science pack are unchanged from Base, only the rails are removed.

(I am currently just using bobgreenhouse_1.1.0 plus the boblibrary in my games in addition to mods from others.)
Edit: Just now saw your new response. Thank you.

I'm not sure when I'm going to release the update fix, but I am aware I should flag this as an urgent update.
It's not the only issue I've had reported related to the recent updates though, so, probably be a few days.

Be aware that nothing added to the recent update is required by any mods, it's purely just cleanup stuff, and other tweaks and updates.
It would be fine to use the previous version of the mod to solve this error until I release an update to fix this issue.

Any chance of an update soon? This bug is causing significant irritation on my worlds, and backdating to just before it causes Bob's Logistics to conflict with Flow Control for Bob's Pipes.

It's also been about four weeks since you said "probably a few days".

Honestly, I made the changes, then kinda forgot about this.

I've uploaded it now.