Let me paint you a picture.
FileMaker 13 uses a legacy activation server. Sometimes that server throws a fit with modern SSL certificates. If you get error "-10001" or "Cannot reach server," here is the fix nobody tells you about: filemaker pro 13 download
The problem? Apple and Claris (formerly FileMaker, Inc.) have buried the download links so deep you’d think they were hiding treasure. Let me paint you a picture