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GitHub User: webdsquared
Thanks for sharing that...solved the issue I was having this evening without having to spend a lot of time searching.
Had the same issue and used the mini_magick gem and all is working fine now. Thanks for pointing that out.
Had the same error...I ended up removing the ENV and  from the CONSUMER_KEY and CONSUMER_SECRET in the devise.rb initializer file. I also used http://127.0.0.1:3000/auth/twitter/callback as my callback URL in the Twitter App settings and it seemed to fix the error for me. In case it matters, in the Website field I used my production url...http://myappname.com. Hope this helps.