The normal protocol of right-clicking your mouse and choosing Copy or Paste for text can be limited in some places in Firefox. The following is an easy workaround using keyboard functions.

Copy

1. To copy, you will just need to highlight the text as if you were going to copy with the right-click of your mouse.
   
2. Instead of right-clicking on the text, you will want to hold down the Ctrl button and press C on your keyboard.
   
3. This will copy the text onto your clipboard and the text will be ready to paste.
   

Paste

1. To paste, place the cursor in the text area.
   
2. While holding down the Ctrl button on your keyboard, press V.
   
3. The text should then appear just as if you would have been using your mouse.