Hey guys, I noticed I had a problem with my Smithing. It allows me to create item of higher quality than I should be able to. I tested this with straight 100 Smithing skill (no fortify effects) and Elven Smithing Perk. I have 86 Light Armor skill with every Perk bar the final one and after upgrading the armor set (helmet, gauntlets, boots, armor) the armor rating is over 600, and I shouldn't be able to hit the armor cap with that layout.

I have Ancient Knowledge ability, for which is said it can cause this, but that was supposed to be fixed by the official patch (And I presume that is included in my Legendary Edition Steam copy?). Regarding the mods, I only have minor smithing mods installed which allow me to obtain Matching Set effect without wearing helmet, and ability to improve Leather, Fur and such armors better with Steel Smithing perk.

I made a new character and gave him appropriate skills/perks and that one is fine (steel armor rating with every relevant smithing/armor perk and 100 skill little over 500). Any way I can fix this? My only guess is that somehow Ancient Knowledge is the problem.

if you are on console try deleting the game data not the saves but a long this benefits you why to fix it?

Lets see here

Elven is light armor, assuming you improved the armor it would still be higher than the base rating (without perks and without leveling)

matching set gives a 25 % boost if the whole set is of the same armor group plus the double resistance plus the upgrading.

Base total = 79 with shield and 58 without.

If someone with a better formula can help me out here I would appreciate it.

Ok for light armor it is this: Armor rating = (base armor rating + item quality) x (1 + 0.4 x (skill + skill effect)/100 x (1 + unison perk + matching set) x (1 + armor perk)

Shield rating = (base shield rating + item quality) x (1 + 0.4 x (skill + skill effect)/100 x (1 + unison perk + matching set)

Displayed = armor rating + shield rating + armor effects (if any)

hidden = 24 per piece

Damage reduction = (displayed armor rating + hidden armor rating) x 0.12

Also there is the Ancient knowlege bug

That is from UESP.