You can ask user to migrate to an iPad or iPhone and use FileMaker Go with your solution.You can continue with the runtimes until they fall apart.To continue distributing your solution with FileMaker, please check the options: Other changes like a new codec for images, some new web protocols or other features will not be supported in runtimes and probably a change in future OS could affect you badly causing crashes on launch or when working with some features. A security policy change, a newer version of MacOS or Windows OS, or a switch in CPU architecture to ARM could stop the applications from working.

But it is time to tell your clients that this won't work forever. You can of course continue for a few years with FileMaker Pro 18 Advanced to create and deploy runtimes. If you still depend on building runtimes, it's time to consider moving yourself and your customers in a new direction. deprecated the FileMaker runtime feature in version 14 and recently announced its removal for the upcoming version 19 in May 2020.

Claris filemaker pro 18