The English (UK) text is bugged

I went on to the Main menu after quitting a world but all the text was replaced by weird symbols (see the attachment). It happened shortly after I downloaded and converted the rescource pack Glimmar's steampunk.
after I switched back to the default rescource pack the text was the same symbols.

Steps to Reproduce:
Note: this is just what happened before I experienced the bug, this may not work
1. Download Glimmar's Steampunk (May work with other texture packs) and convert it into a rescource pack.
2. Use it for a few minutes, then quit the world you are on.
3. All the text should now be replaced by weird symbols.