I found that in some situations FileMaker 17 doesn't close properly.
With no file open is it impossible to close FileMaker application and I need to kill the app.
I found this situation when FileMaker is hanging.
Workaround: kill the FileMaker app.
macOS High Sierra 10.13.5
FileMaker Server 220.127.116.11
FileMaker Pro Advanced 18.104.22.168