using copy/paste in-game causes game to crash

I had to reset my PC and had just re-installed Minecraft and was re-adding my favorite servers. I went to copy/paste the IP when the game crashed and the launcher came up. I tried again by pasting into the chat while on one of my singleplayer worlds but the same happened.

I then tried on version 1.11.2 with Optifine mod but the game crashed again when I tried to Ctrl+V. BUT this time when the launcher came up it said:
"It looks like you are using an unsupported modified version of the game."
AND gave these details:

"The game crashed whilst updating screen events
Error: java.lang.NoClassDefFoundError: java/awt/datatransfer/FlavorTable"