Installed Mojave, then my mac couldn't start the next day, now it asks to install Mojave again From High Sierra, I was prompted to upgrade to Mojave; did that, successfully completed (I guess, no errors were reported or something, but I don't remember if I restarted my laptop at that point. Moreover I didn't check if the version was upgraded in "About this Mac".).

Next day, I try to start my laptop, nothing... Eventually it says there was a problem finding the launcher or something. Laptop started successfully (phew!), and High Sierra is still installed.

Now, it asks me to upgrade to Mojave again, but I am afraid. What are the risks in accepting to upgrade? What should I do? Maybe I could stick to High Sierra...
What should I do?


If it were me, and my machine was running at this point, I'd backup the disk, then separately backup my home folder, and put those media aside. Then I'd redo the upgrade.