Issues with Apple Wallet...

When adding my Southwest boarding pass to Apple Wallet, I get this error: "The pass cannot be read because it isn't valid." I've tried hitting the "Add to Apple Wallet" button in the Southwest App. I tried clicking the passbook.pkpass attachment in the email I received from Southwest. Even tried scanning the barcode after printing the pass but it doesn't recognize it. I've also tried restarting my phone (iphone 6s plus running version 10.2) and deleting and re-downloading the Southwest app. I have also searched here and on Google for answers and I seem to be the only one that has this problem...

Help?