#2 Aug 18, 2015 21:48
@lus as I said you in the plugin's page comment, this issue has already been solved, so the best advice I can give you is to upgrade your site to the most recent version (6.6.2 right now). You will see it's worth each one of the five minutes the upgrade takes (if no weird issues appear during the process ).
There is also a workaround that might help you to solve this right now, while you take the decision to upgrade your site. Please check this comment: http://forums.b2evolution.net/cant-link-to-twitter-with-plugin#c104186