Cause

You have placed a connector with separate male and female pin representations in the schematic. A corresponding symbol with a direct connection is used for male and female pins.

Male and female pins also have the same DT, the same designation for each pair and the corresponding settings for assigning male and female pin sides (on the male "male side, on the female "female side"). The function definition on one of the male or female pins is, however, set as opposite (on the male pin "female pin, 2 connection points", or on the female pin "male pin, 2 connection points").

Solution

Change the function definition in the Properties <...> dialog for the relevant male or female plug. For the male pin choose the setting "Male pin, 2 connection points", or for the female plug choose the setting "Female pin, 2 connection points".

Refresh the connections and then start a new check run.