I had the same problems. Solution? Went back to 10.14.5.Everything went smooth but now I can't change fanspeed and HWMonitor keeps asking me for a password to install new "helper tool" everytime I try to change the fanspeed. Doesn't seem to be changing either, did anyone else have any issues with fakeSMC sensors and HWMonitor not changing the fanspeed this update?
I made a thread here if anyone is able to help https://www.tonymacx86.com/threads/hwmonitor-keeps-asking-to-install-new-helper-tool.285260/
I have seen here on tonymacx solutions to your problem. If you search using these key words, "installer data was missing" then you may find a solution.Updated, some issues...
While updating, after a couple of reboots it stayed on the installation boot saying installer data was missing. Rebooted and manually selected the Mojave boot and after a couple of trials it boots there, still running like that an a pain to boot each time. Once booted 10.14.6 (18G103) appears to work correctly, so installation did completed but missed the last bit of the procedure.
The preferred boot is still the installer and keeps doing the same thing, the synthesized volume still appears, as expected, given the issues, check the attachment. Any ideas how to erase it without messing the OS?? I guess just by doing so it will go back to normal.
Any help appreciated.