I had the same issue that I couldn't mount InstallESD when creating a sierra UniBeast Drive. After much searching I found a reference to MTU frame sizes. I worked out my optimum MTU setting (plenty online how to do this) and set it in the Network settings on OSX. I then re downloaded the Sierra...
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.