If only single sea tiles have to be jumped, adding should be possible but it is bugged in many or all cases. I think the CB should not be available if the game would have to jump over more than one sea tile while adding provinces to the HRE. The problems start if some provinces can be added but not the capital. If all provinces share a land border with each other adding the country to the HRE works. If a country has no such province you don't get the CB. For a province to be added to the HRE it needs to be christian, in europe and it either needs to border an HRE province or share a sea tile with an HRE province. Originally posted by grotaclas:I think this happens if a country has disconnected provinces and they can't get added to the HRE one after the other.
