"There is not enough free space" in Catalina installer - beware, people are getting stuck here!

[bkendig]

I tried to install Catalina on my Mac mini (2018) last night. The installation proceeded normally until the first reboot, at which time it showed a screen that said:

macOS could not be installed on your computer
There is not enough free space on Macintosh HD to install
Quit the installer to restart your computer and try again.

I quit the installer. It rebooted, and brought me back to the same message.

I wasn't able to find any way to get back to my previous Mojave installation. Eventually I had to restore from a Time Machine backup, which took all night. The other option would have been to reinstall Mojave and hope it kept all my files.

Other people are seeing this problem, too:

16 Common macOS Catalina Problems & How to Fix Them

This is how you can fix macOS Catalina problems on your Mac. In 2020 we’re seeing new macOS 10.5.5 problems pop up including file transfer issues and sleep issues. Sometimes you will need to wait for Apple to release a new update, but for the most part, you can solve macOS Catalina problems on...

www.gottabemobile.com

https://www.reddit.com/r/applehelp/comments/depv73

https://www.reddit.com/r/MacOS/comments/deuwsa

https://www.reddit.com/r/applehelp/comments/df0zb8

So, before you try to install Catalina, make sure you have as much free disk space as possible and make sure you have a current Time Machine backup!

 

[harriska2]

I take it you have 128gb drive?

 

[bkendig]

No - it's a 256 GB drive with 70 GB free.

 

[IowaLynn]

Reminds me of BootCamp. Not enough free space could mean contiguous or too fragmented and licked files that couldn't be relocated.

Setting up the new read-only system partition.

Backup, boot off another drive, reformat erase and it will be easier.