P: $$$/CRaw/Error/Unknown=There was an unknown error. (1)

Your comment helped. Not the exact steps but the same principle of creating "Select Subject" mask, not doing anything with it and re-attempting the export. It worked. Thanks!

I am having the exact same issue. But it is random. I batch export to JPEG in medium resolution, all exported without issue. I batch export the same files in lower resolution for use on Web, and only 3 files will not export. I close LR and relaunch and attempt the explort again and it has always worked in the past but today it is stuck. No matter how many time I relaunch LR, those 3 files will not export. Then I created a new mask "Select Subject". Tried export. Failed. Then I deleted the mask, tried export, worked. In the same instance of LR, without relaunch. But, now when I click on any other thumbnail in the filmstrip, it countinues to show the exported image in the Develop window. These are all images that have the "Select People" masks with each separate feature ( iris, teeth, lips, etc.) created as a mask. The "GPU Rendering" circle at bottom right in LR Develop mode, continues to rotate. The creating new mask "Select Subject" seems to have worked for me for now. Images are exporting fine as JPEG after that. ( Massive apologies for the jumble of text above but it's literally trial and error till the bug is fixed - assuming it's a bug.)

One other thing i'd like to add regarding this issue.

As a workaround, anytime i encounter it, i just export the picture as png, instead of jpeg and it works.

Is there a way to get in touch with anyone working on Adobe about this issue? Or, how do i report it?

It really sucks having to batch export everything as .png..

I have occcasionally the same problem exporting files. When I don't adjust seize there is no problem. The helpdesk didn't give me an answer. Is this a bug?

Try downloading 12.5 

i'm also having this problem, and its seems i'm the only brazilian facing this hahaha not even adobe support can explain to me whats going on (i've tried to downgrade to v12 but the error continues to appear), tried everything i could 😞 

Continued to play a bit with this issue, using the same "problematic" raw.

I think it has to do with the masks (i use a subject and an inverted subject).

What i tried:

- Deleting/hiding both masks exported OK;

- Creating new masks with same settings - NOT OK;

- Having one subject mask, with exposure/contrast/highlights/temperature modified/texture and clarity - NOT OK;

- Using same mask as above BUT with removing texture and clarity - OK

- Adding a second inverted subject mask and leaving it empty - OK;

- Tweaking just the exposure on this second mask - NOT OK.

By OK i mean export worked as JPEG, by NOT OK i mean export didn't work as JPEG and received the titled error...

"I'm using Lightroom 13 on a Mac mini pro with m2 chip 

I keep getting an error message saying 

$$$/CRaw/Error/cannotread = there was an error parsing the file 

the error comes when I use adaptive sky on my images 

is there a fix for this ? "

Well you could start by not hijacking a thread about a different issue...

Update #3 (sorry for the chained comments): Exported a raw as jpeg, worked. Applied some AI NR on that same edited raw and then i tried the export the resulted dng as jpeg, it failed. Same dng exported as png worked.

Small update, can't seem to edit my previous message.

I exported other raws from the same folder (catalogue) and it exported just fine.

Then i tried exporting the same "problematic" raw as png and it worked. Tried again as jpeg and it failed.