Thank you for the suggestion, Jvstratum, The left menu, collapsed, is hiding the debug text. However, I could see enough info to help troubleshoot.
It appears that when the first migration locked up, it loaded enough information to create errors when making a 2nd attempt (duplicate entries) . I uninstalled V6 and removed all database tables to start again.
After re-installing, I went to the main V6 admin page to migrate again.
----Javascript Errors in "inspect"----------
GET https://code.jquery.com/ui/1.11.4/jquery-ui.min.js net::ERR_TIMED_OUT
back_global.min.js?v=1577719082:9 Uncaught TypeError: t(...).sortable is not a function
at HTMLDocument.<anonymous> (back_global.min.js?v=1577719082:9)
at fire (jquery.js?e21fc8a3290dbaf7341ba5a0d83a41d4:3235)
at Object.fireWith [as resolveWith] (jquery.js?e21fc8a3290dbaf7341ba5a0d83a41d4:3365)
at Function.ready (jquery.js?e21fc8a3290dbaf7341ba5a0d83a41d4:3585)
at HTMLDocument.completed (jquery.js?e21fc8a3290dbaf7341ba5a0d83a41d4:3620)
It's also showing duplicate entries in the qza_acymailing_config table.