If you don't trust third-party downloads, you can create your own updated pack:
If you downloaded a pack labeled "updated" and it fails, try this checklist: minecraft 1122 fullbright texture pack updated
A Fullbright pack is a resource pack that alters the game’s lighting mechanics—specifically the "lightmaps"—to remove darkness entirely. It essentially maxes out the brightness of every block and biome, turning night into day and illuminating caves without the need for torches. If you don't trust third-party downloads, you can
Why use it?