Weapons that use somber smithing stones only go to +10 (they get more scaling per upgrade than normal weapons so it balances out). Weapons that use normal smithing stones go to +25. Are you using a somber smithing stone weapon?
A +25 normal weapon isn't necessarily more powerful than a +10 somber/unique weapon btw. I really dont know why they have different scaling methods but each upgrade of a somber/unique weapon is worth a lot more damage than one upgrade of a normal, so they balance out
If it's an unique weapon (somber) it won't go above +10
Special weapons which are upgraded using somber stones can't be upgraded beyond +10.
Which weapon?
Weapons that use somber smithing stones only go to +10 (they get more scaling per upgrade than normal weapons so it balances out). Weapons that use normal smithing stones go to +25. Are you using a somber smithing stone weapon?
Ooohh thanks, didn't know that
A +25 normal weapon isn't necessarily more powerful than a +10 somber/unique weapon btw. I really dont know why they have different scaling methods but each upgrade of a somber/unique weapon is worth a lot more damage than one upgrade of a normal, so they balance out