

Scroll down the options on the left until you find Full Disk Access and select it. Go ahead and click on that and then navigate to the Privacy tab. Open the macOS System Preferences app and find the Security & Privacy button. Warning 156 Schedule "HOURLY_BACKUP_USB" aborted the destination "filemac:/BackUps/" is not writable. If you're getting an error log like this, then read on for how to fix it.

We've experienced this on FMS 18 after upgrading the operating system, and after installing FMS 19. However it can create some headaches, and one of these seems to be interfering with FileMaker Server backups to external USB drives. Security is good though right? Yes, absolutely. If you've used Catalina, you'll know that at every turn you're asked to authorize an app being opened for the first time for access to your documents or other folder, to send you desktop notifications etc. MacOS Catalina introduced a swath of new features and changes, including a whole bunch of security adjustments. Although apparently fixed in FileMaker 18.0.4, it's rearing its head again, but there is a simple fix. If you upgrade your Mac server to macOS 10.15 Catalina, you might find that your backup schedules to external drives start failing with an error number 156.
