Setup Wizard Crashes

I have tried everything I can think of and it always fails.
I have installed the latest version on an existing site and every time the wizard runs it crashes on the Content tab. In my logs, I see something like this:

WordPress database error Duplicate entry ‘8-15’ for key ‘wp_4_term_relationships.PRIMARY’ for query INSERT INTO wp_4_term_relationships ( object_id, term_taxonomy_id ) VALUES ( 8, 15 ),( 6, 16 ),( 8, 17 ),( 6, 18 ),( 8, 19 ),( 6, 20 ),( 8, 21 ),( 6, 22 ),( 8, 23 ),( 6, 24 ),( 8, 25 ),( 6, 26 ),( 8, 27 ),( 6, 28 ),( 8, 29 ),( 6, 30 ),( 8, 31 ),( 6, 32 ),( 8, 33 ),( 6, 34 ),( 8, 35 ),( 6, 36 ),( 8, 37 ),( 6, 38 ),( 8, 39 ),( 6, 40 ),( 8, 41 ),( 6, 42 ),( 8, 43 )

Have spent over 6 hours trying to come up with ideas.
I have even disabled all other plugins and it still fails.
After failing it wrecks all my Categories and Tags and I cannot properly add them manually as the English flag never appears.

Have also tried installing a previous version.

Any help would be appreciated.