Add rates does not work

Add rates does not work, and is a total mess.

There are dropdown menues for the country and the state, but you have to fill the fields manually. In addition to this you have to define a city and give a postcode. Enter all cities with their postcodes of a all states of different countries will be an endless work… Or have I missed something?

Despite of this when I try to add a rate I get the following error message:

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