It is quite easy in yur unit test...you don't need to create any class since everything is done with static methods.

You just set manually your Thread UI culture to the neutral one (en-us) and read the list of all static  property names.

Then you do a loop on all supported culture, where first set the thread UI culture to the current loop culture, and then you read all property values. In case some value is wrong in a culture you will get either an exception or a empty/null value. This is your error condition.