Mojave update 10.14.6 will not complete installation, every attempt ends with an error message that just says there was an error
What's going on here?
Open Disk Utility and run First Aid on your disk, if any errors are noted then boot to your Recovery HD and run Disk Utility First Aid from there until the errors are gone.
Download this, https://support.apple.com/kb/DL2010?viewlocale=en_US&locale=en_US once downloaded double-click to install.