Hello Peter,
I am using Conditional Content on our home page: This is our Supply Chain Control Tower. {show accesslevels="Guest"} Login to learn more. {/show}

This works. We use it on several sites.
Except.

I played around with getting rid of the Guest user group since we don't really use it. Ok, dumb idea, for more reasons than one.
I recreated the Guest user group.
But now, the code doesn't work. I thought perhaps you refer to the ID for Guest instead of the Title? The new id for Guest is now 20. On another system, the ID is 9. I tried changing the ID to 9, but that doesn't work either.

I tried inserting your example code:
Even when I am not logged in it tells me I am a registered user. When I log in as Super User, it still says I am a Registered User.

I have reinstalled Conditional Content, and applied updates to Sourcerer, et al.

I can use other conditional content such as {show date=">2023-05-10 12:42"}Hello today is May 11{/show} This works.
Looks like I broke the accesslevel area of Conditional Content big-time and need to reinstall from a backup....
Any ideas before I do so?

Ahh... quite right. I jumped to the conclusion that it was deleting the user group Guest that caused the problem.
I never deleted the Access Level Guest, and yet, the conditional code still doesn't work.
I understand quite a lot about how to set up groups and access levels...

Anywhere I could look to find out why the conditional code accessing Access Levels no longer works on my site?