FileMaker, Inc. is planning to release an update of FileMaker Pro 15, FileMaker Pro 15 Advanced, and FileMaker Server 15 in the near future to address compatibility issues with macOS Sierra 10.12 as well as other general bug fixes.
These are the know issues to date:
|FileMaker Pro 15 / FileMaker Pro 15 Advanced||15.0.1||
||Install FileMaker 15.0.2 Updater
|FileMaker Server 15||15.0.1||
||Download and install FileMaker Server 15.0.2
The timing and scope of these updates are subject to change at the sole discretion of FileMaker, Inc.
As always, I recommend waiting until FileMaker themselves confirm that FileMaker 15 is compatible with Sierra. Until then, hold off on doing any upgrading.