Cause
A pin is used multiple times with the same full DT on the project schematic pages.
Solution
Locate the multiple pins in the schematic using the Go to menu options or double-click the output messages in the Message management dialog. Call up the Properties <...> dialog for each of the found pins and compare respectively with the full DT. Assign each of the multiple pins to another full DT by assigning unique pin designations.
Note:
Female and male pin pages can be represented separately from plug-in connectors in EPLAN. There are special pin symbols for female and male pins provided for this purpose. Male and female pins may have the same pin designations if they belong to the same plug-in connector, i.e., are counterparts. On the other hand, pins of the same type at the male and female ends of a plug must have different designations.
Refresh the connections and then start a new check run.