Copy and Paste Broken

Hello!

I am trying to copy and paste a seed into the world generator, but I found I was unable to. Then I tried the world name and chat, and neither let me copy and paste. I know it isn't my clipboard because I can paste it into all other programs.

Reproducing:
1. Start Minecraft as normal
2. Copy a seed (or anything) from anywhere
3. Try pasting it into the chat, world name, or world seed slot using CTRL + V

I can provide a fake crash log if you like, or anything else.

Thanks for the help!