Adobe Flash Player - Downloads - make sure you download the highest version you can find for your operating system. Realm stopped working with older flash players a while ago. Also make sure that you download the one that doesn't say debugger in it as you don't need it and it slows down the game some (plus, with any error you'll get popups which you don't need while recording).
---------- Post added at 07:15 AM ---------- Previous post was at 07:13 AM ----------
Also make sure your .swf is hacked to connect to production servers if you'll be recording on them.