NOTE: This bug has been completely resolved with the new Sync.jsx script. Updating to the new version should fix this problem!
Some users have been experiencing an issue (specifically after updating to OS X10.11 El Capitan or later), where starting the Sync_3.jsxbin script will cause InDesign to freeze... this tutorial will tell you how to fix that!
1. Start Sync From InDesign
First things first... start your Sync from InDesign by using the keyboard shortcut command+shift+2 (Mac)
If you're experiencing this error, it will appear like nothing is happening, and InDesign will become non-responsive...
HOWEVER, what is actually happening is that the Sync Script is running normally (but without the progress bar in InDesign)
When InDesign is ready, you can switch to FileMaker and press Sync, as usual. But how do you know when InDesign is ready?
2. Check the XML folder
When InDesign is ready, it will export a file entitled from_ID.xml to the XML folder of your SignAgent Pro™ folder.
So, to verify that this has happened, just check the modification date on that file.
3. Switch to FileMaker and Press SYNC
Once you've verified that from_ID.xml has been modified, you can now complete the synchronization by switching to FileMaker Pro and pressing SYNC.