I received an email today from FileMaker Inc. saying an update to FileMaker 15 is in the works and please hold off from upgrading to macOS Sierra until FileMaker Inc. gives the go ahead. Past experience has been that it may take a couple of weeks before a new update is available and FileMaker gives their OK to run FileMaker 15 with the new OS.
If you need to run FileMaker Pro 15, safely, we strongly recommend you postpone this upgrade until you hear from FileMaker.
Previous versions of FileMaker may not ever be certified as good with Sierra. We have seen that sometimes after a much longer delay, like a year or more, the immediately prior version or 2 of FileMaker Pro may get less than certification but an OK to run with typically a few issues and limitations.
At this point, if you want to upgrade to Sierra when FileMaker.com says ok or not, we recommend you upgrade to FileMaker Pro 15 to run recent versions of Studio Manager. We are happy to answer your questions if you need further assistance (Janet’s iPhone: 415 272-8563).