I ran into the same problem today. I received the "Uncaught TypeError: Object [object Object] has no method 'select2'" error message in my browser console as well as a warning about a deprecated method in another .js file I was referencing (http://code.jquery.com/jquery-1.9.1.js). Turns out I wasn't even using it! so I deleted the script which referenced it, removing the warning.
Fixing the warning made my select2 problem go away.
a few things to help you trace what's wrong.
- Are you able to get select2 to work in the most trivial of situations? (strip everything else from the page and ONLY use a select2 droplist to make sure your select2 libraries are working)
- If you can get #1 to work I'd wager you have some javascript in another file which is interfering with your select2 droplist. Disable other js features one at a time to see which one is the culprit.
- Good luck! keep an eye on your console and network tabs to be sure your js libraries are loading and don't have errors or warnings.