Product and version:
FileMaker Pro 16.0.2/15.0.3/14.0.6 and FileMaker Go 14.0.4
How to replicate:
1. Buy SSL certificate for 3 years (expires after May 2020) from Comodo.
2. Install the SSL certificate and the intermediate certificate (COMODO RSA Organization Validation Secure Server CA) to FileMaker Server 16.0.2, enable SSL and restart the database server.
3. Launch FileMaker Pro (or FileMaker Go 14) and connect to the server. (SSL connection works well at this time.)
4. Quit FileMaker Pro (or FileMaker Go).
5. Change the clock of the client device to 2020-06-01.
6. Launch FileMaker Pro (or FileMaker Go 14) and connect to the server.
SSL connection works well without error.
FileMaker Pro 14.0.6 and FileMaker Go 14.0.4 can't connect to FileMaker Server with SSL connection.
SSL connection doesn't work with FileMaker Pro 15.0.3 and FileMaker Pro 16.0.2 for Windows and macOS. (FileMaker Pro shows an SSL expiration error.)(Not tested with FileMaker Pro/Go 13 or previous.)
Workaround (if any):
This issue is not affected at this time. (Affected after May 30, 2020.)