SMF has changed their cookie system with the release of 2.0.16. Therefore, integrations and modifications that need to tap into SMF's cookie will need to be updated. You can read about it here...

https://www.simplemachines.org/community/index.php?topic=570989.0

Are your premium mods going to work with the new HMAC method of cookie generation? 

I am currently using the following SMFPacks mods...

Two Factor Authentication CR
Mentions Mod Copyright Removed
SMFPacks Alerts Pro CR
Social Profile CR
SMFPacks Profile Popup CR

Of course, only two factor authentication will be affected by this change