It is the same as this guys last post.
https://forums.spongepowered.org/t/forge-only-missing-english-translation-for-minecraft-minecraft-jar-no-such-file-or-directory/20375/5
Hello guys.
When I start my server I receive warning messages that some en-us.lang files are missing by FileNotFoundExceptions such as: assets/mcp/lang/en_us.lang and assets/fml/lang/en_us.lang. When I look in the jar they also seem to be missing. What can I do to fix these warnings? Is it bad that I get them?