Cause

Possibility 1

The mounting rail containing the part placement was retrospectively shortened. Although the part placement is still logically assigned to the mounting rail in the layout space navigator, it has become detached from it graphically in the layout space.

Possibility 2

The Center mismatch and / or Clip-on height parts data for the part placement on the mounting rail was subsequently changed in the parts management dialog (Mounting data tab).

Solution

Regarding option 1

Place the part correctly on the shortened mounting rail or extend the length of the mounting rail so that the part placement is on it once again.

Regarding option 2

Undo the change to the Center mismatch and / or Clip-on height part data in the parts management dialog for the selected part placement or place the part again with the changed part data.