We just got notice on the compatibility from FileMaker:
More details in the knowledge base article.
FileMaker Pro 17 Advanced is compatible with macOS Mojave 10.14 with known issues. A compatibility update is planned for the November/December 2018 timeframe.
FileMaker Server 17 is currently not compatible with macOS Mojave 10.14. A compatibility update is planned for November 2018.
FileMaker Go 17.0.3 is compatible with iOS 12.
For MBS FileMaker Plugin, we release 8.4 tomorrow with the latest fixes for macOS 10.14.