My 2019 iMac will not boot into Safe Mode

Thank you. That did help. I had found that article previously but failed to notice the bottom of it and how it could apply.

Unfortunately, it didn't get me all the way there. The terminal command it advised me to use:

sudo nvram boot-args="-x"

resulted in an error:

nvram: Error setting variable - 'boot-args': (iokit/common) general error

So I had to go searching for how to get around that. Turns out that article was last updated in August of 2017, and they have not added the one necessary step prior to that, which is to:

• boot into Recovery Mode
• Open a Terminal Window
• Then: issue that nvram command

Thankfully, I do have a keyboard and it did allow me to boot into Recovery Mode via the Command-R key combination. I was then able to boot into safe mode. I am curious to why the iMac responds to my Cmd-R for Recovery, but not my Shift for Safe.

I do wonder what the solution is for the keyboardless, given the section in that article's heading, "If your Mac doesn't have a keyboard to start up in safe mode or if you can't use the Shift key". Hm.