Background: Several of our clients jumped the gun and installed macOS 10.14 Mojave the day it came out. Unfortunately, they were among the first to discover that FileMaker does not work well with Mojave, as they were unable to connect to their remotely-hosted databases and experienced crashes. Following up on these reports, we installed Mojave on one of our MacBooks and confirmed this behavior for FileMaker 17, 16 and 14. (N.B.: FileMaker 17 and 16 are supposed to be able to work on Mojave, while earlier versions of FileMaker are not supported.)
FileMaker's Comments: According to FileMaker, FileMaker 17 and 16 are compatible with Mojave, but with known issues. An update to make them fully compatible has been targeted for no later than December of this year.
Regarding FileMaker Server 17 and 16, FileMaker has acknowledged serious compatibility issues between those two programs and Mojave. As a result, FileMaker recommends against installing Mojave until updates for FileMaker Server are released. The updates are expected by the end of November 2018.