Put the summary of the bug you're having here
-Fireworks aren't showing
What I expected to happen was...:
-I've deleted Meta-inf folder
What actually happened was...:
-When You let fireworks, then You lose the item and you can hear only the sound of starting but
you can't see it and you can't see explode (hear it too)
Steps to Reproduce:
1. Open the C:/users/user/appdata/roaming/.minecraft/bin
2. Open the minecraft.jar file with 7zip or winrar
3. Delete the Meta-inf folder
4. Close folder and winrar (or 7zip)
5. Run minecraft
6. Play on singleplayer or multiplayer
7. Craft or get from creative this firework
8. Put in anywhere
9. Hear...
10. See...
deleting the META-INF folder is considered modifying the jar. This Bug Tracker is for vanilla bugs only.
(Although the META-INF folder should only contain a manifest file and shouldn't have an impact on the game itself)