I can't open FileMaker Pro Advanced 15, whether from a local file; or from the application, when my MacBook is set to use a manual proxy address e.g. proxy.somewhere.com:8080. It just will not open. I have to force quit. Sierra is not good with proxy handling and the combination of proxy, OSX and Filemaker is a shocker. I have filed a bug report with Apple on the proxy issues in general - and the fact that OSX and IOS now request to open Network Preferences when they encounter a proxy. A keystroke that disabled FM Pro for looking for hosts on startup would be ideal.