Our activation system may have changed. The current version of Episode is 7.4.
Fill out the form and we'll get back to you. Note that it's an Activation issue.
Episode Support Form
Keep in mind Episode 6.5 may not be compatible with the operating system on your new mac. Episode 6.5 would need Yosemite (10.10) and may not work on more recent operating systems. El Capitan requires 7.0 and Sierra 7.2.