This was from before the value pack upgrade, if you already did the upgrade, it will mess up your phone. Also, you don't need it if you are using a AT&T phone, it is the same, just a different modem.
If you want to make it work, this may not have the permissions set correctly. Also, when you try it, take your stock messaging .apk and change it to .bak, then add root browser to your lock screen in case of an issue you can go right in and delete it and change your original that is .bak to .apk and all will be fixed.
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