Defpoints layer

Why can I not always select something on the Defpoints layer?

I have always created a new viewport in layout space on the Defpoints layer and been able to select the viewport to move it, etc.

However, I have a couple of drawings that I can't even select anything I put on Defpoints - lines, text - anything.

Is there a variable I've changed and don't realize it?

Thanks.

If I had searched first, I would have found my own answer - if layer 0 is frozen, you can see defpoints, but you can't select.

I'll do my own face-palm now.

Thanks.

That's why it is recommended not to use defpoints layer. Make a custom Non-plot layer instead.