Cuando descargo un mod se me bugea y salen letras en la pantalla

Bug de modsPut the summary of the bug you're having here

What I expected to happen was...:
Im donwload a mod an my minecraft bug in the screen numbers an leters

What actually happened was...:
Im donwload a mod an my minecraft bug in the screen numbers an leters

Steps to Reproduce:
1. Put a step by step guide on how to trigger the bug here
2. ...
3. ...