Sometimes the “find broken link” command find a corrupted PDF. Usualy it appears as a second pdf attached to the reference. In Endnote 9: very easy: just delete the corrupted attachement, the good one survived and everything was OK. In Endnote 20, if you do that, the file you did not delete appears now as corrupted. Impossible to open it. You has to delete it also and attach the original file of your attachement (just hope that it is still available…). On another occasion, I tried to delete the non corrupted one, just to see… same result, only a corrupted attachement subsists. Endnote 20 is deeply deceiving for that reason and all the others already pointed by the community in this forum.