The same thing just happened to mine. I have no idea, maybe a sunburn?

We haven't had much sun in Minnesota but it does look like it could be sunburn. I beheaded them all and moved the pot. Maybe they will recover.

Yes!

Leaves could be cracking from too much water - oedema.

It could be a mechanical damage too - something falling on top of the rosette when it was more closed yet, leaving scratches/marks on all leaves that got 'hit' (or squashed).

Another possibility could be some bugs (or even snail?) or pests trying to feast on juicy new growth (same as above).

Just guessing, it doesn't look like a disease.

Thanks. Hopefully beheading the tops will help?

Carol

I am not sure what you mean - beheading will not change anything existing on leaves, but they will eventually grow old and dry up and be replaced with new leaves. You can behead to make longer stems short, if you like.

Hopefully the new growth will be healthier.

Carol

Any possibility of something falling on them - or pests munching? It looks almost like scratches - do you have cat? They like to dig and play with plants :) I noticed few small spots on Anacampseros next to it. Just in case you find out what caused it, pls. post.

Oedema usually shows up as small, pimple-like dots but could be also bigger spots. Cracking may occur if really too much water, probably suddenly. Over all, probably not too much worry about since it looks more like a one time damage.

No cats..no trauma to the leaves. Haven't seen any critters. Will post if I solve the problem..thanks

Same here, the only possible option seems to be oedema.

Could possibly be damage by thrips - small flying insects that can easily be missed.

Thanks Andrew. Will keep a watch out for those little critters.

If there are thrips, they should be destroyed. IIRC, they multiply quite fast. I am not sure, but think they can be spotted, since there are winged and wingless forms.