I'm having the same problem with Backup and Restore (Windows 7) on my Windows 10 computer running the latest 1809 version (October 2018 update). After reverting to the previous Windows 10 version (1803, April 2018 update), that backup program works again.
The free version of Macrium Reflect seems like a good program, but I don't want to just make system image backups, I also want to back up and restore individual files (kind of like Time Machine on Mac OS, I choose the folders to back up, the backup program syncs the contents, and I can restore some or all files, even on other computers).
I'm sure third-party backup programs work well, but I don't know how much I should trust the free ones, and I'd like to avoid paying upwards of $50 for an alternative to something that is included with Windows for free, and stopped working because something else in the operating system has changed and broken this deprecated feature.
I don't want to use File History because it's too limited. Microsoft discontinued a feature without offering a suitable replacement. I think a small fix for this program could be made, but I'm afraid it's not happening.