It looks like, you have the error of "the Installer Source is damage" issue, you should check the md5 first.
It could be the network issue when you download the full installer with "Q6-DownloadFullApp/installScript_1014fullapp",
and didn’t get the complete installer app, especially the big size one "InstallESD.dmg".
Check md5 with Terminal command:
md5 "Install macOS Mojave.app/Contents/SharedSupport/InstallESD.dmg"
mac OS 10.14.0.18A391
-rw-r--r-- 1 501 2890005 9 25 07:21 /10.14.0.18A391/Install macOS Mojave.app/Contents/SharedSupport/AppleDiagnostics.dmg
-rw-r--r-- 1 501 481796638 9 21 20:25 /10.14.0.18A391/Install macOS Mojave.app/Contents/SharedSupport/BaseSystem.dmg
-rw-r--r-- 1 501 5526130487 9 21 20:30 /10.14.0.18A391/Install macOS Mojave.app/Contents/SharedSupport/InstallESD.dmg
MD5 (/10.14.0.18A391/Install macOS Mojave.app/Contents/SharedSupport/AppleDiagnostics.dmg) = dd937905f9148bb4c46672dda021d158
MD5 (/10.14.0.18A391/Install macOS Mojave.app/Contents/SharedSupport/BaseSystem.dmg) = 871f5701af49f91de69edd2ac164c481
MD5 (/10.14.0.18A391/Install macOS Mojave.app/Contents/SharedSupport/InstallESD.dmg) = e603e94dd99241bab4938a7f0334ba1b