You may want to wait on updating to OS X 10.11 El Capitan, please see this support article from FileMaker:

If you have already updated to OS X 10.11 El Capitan and are using 360Works plugins, read on.

360Works plugins are compatible with OS X 10.11 El Capitan, however, during the process of operating system update Java 6 is removed. And, when first launching FileMaker Pro after the os update you may encounter the following dialog:

Clicking 'More Info' will take you to this Apple support article:

Where you can download the Apple Java installer. Use this installer to re-enable Java 6 on OS X 10.11.