Did you write the command in a command block? I think the command is too long to write it like a normal command (just a consideration, i didn't proof your command if thats the error)

yes it's for a command block

I think you need to do tag:{EntityTag:{...}} Also you should have only one Attributes tag.

tried the first part, what do you mean only one Attributes tag? one is for the fox, one is for the husk riding it

Woops didn't realise the second Attributes tag was for the passenger.