MacOS Mojave update stuck

I had the same issues and just got it resolved.

I reinstalled OS on an external drive and boot up from there. Then deleted some files to create more space. I was having 95gb left and deleted another 200 Gb.

After that I downloaded the Mojave OS and reinstalled on the Mac, and it worked.

I had this exact issue, progress bar stuck at completion/near completion. Here is how I was able to fix.

The only fix that worked was Recovery Mode (hold command +R immediately after

power on, until Mac goes to recovery mode). On/off restart, NVRAM/PRAM, Safe Mode, and Reset SMC all did not work and I tried them all.

I launched Recovery Mode, the WiFi connection indicator was “off”. I connected the WiFi, had to login. Next, I ran the Disk Utility, and then shut down (attempts at a restart resulted in the incomplete status bar). I ran Recovery Mode a second time and again had to connect to WiFi. Finally, I ran Reinstall MAC OS X.

This fixed the issue, no data was lost, all settings were the same as prior to the update.

I am curious if the disconnecting WiFi leads to the install not being able to complete. At any rate this worked for me.

Thank you so much