Same Issue here. Spoke with Adobe Muse Chat support....they told me to :
Rohit N: What you can do is, Login to your GoDaddy account. And from there you will have to disable EPSV.
Rohit N: This can be done by adding : <Limit EPSV>
Rohit N: DenyAll
Rohit N: </Limit>
Rohit N: to proftpd.conf
Have no idea how/where to perform this change on GoDaddy.
Will call GD today....but seems a bit of a messy workaround.
Hopefully Adobe will address.