Error 21: undefined is not an object

ciao a tutti aggiornato a 26.5 e beta 26.6 su entrambe le versioni si ripresenta l'errore 21 e ligthroom classic V14.2 non carica più il file al salvataggio di PS.  Non vorrei fare downgrade, qualche suggerimento?

I don't know if this is a solution or just a coincidence. But, the problem kept returning for me with every new PS update. Then I read somewhere someone mentioned something about having this issue when using the 'Edit In Photoshop' feature in Lightroom, which is what I do, too. So I tried opening a file outside of Lightroom and didn't have the problem. At that point, I realized I had 'Maximize Compatibility' turned off. I turned it back on and haven't had the problem since. For anyone having this issue, try turning Maximize Compatibility on and see if it solves the problem. It's worth a shot if nothing else works. 

Spoke too soon. Downgraded to 24.6 and the problem went away. So on a whim, I tried upgrading back to 24.7 and sure enough the problem was gone...so I thought. After several weeks error-free the error is back again. So annoying! So I guess I have to keep reinstalling every few weeks? PLEASE fix it!  

All of a sudden, I am having the same problem. 

When I am in LR and click on "open image in PS", PS will open but the image isn't showing up. Only way to open is when I open it as a spart object. 
Then when I try to save it back into LR, it won't show up in Lightroom. UGH! I updated a week ago or so and the problem just started

I updated PS to 24.7.0 today, and then I noticed that I could not save my files as I usually do (from Lightroom to PS and back again).

When I use the shortcut command S I get the error message Error 21- undefined is not an object.

I'm on a Mac M1 - Ventura 13.3.1(a)

Does anyone else have this problem and know a solution for it?

downgraded It with a lower version , the problem is in Lightroom last update , have that problem 

same happend to me , i have apple MAC M2

I have/had the samer error on Photoshop 24.7 (MacOS M2Pro on Ventura 13.5), and it was fixed for me by uninstalling 24.7 using the Creative Cloud app (saving preferences), and then reinstalling 24.7 (same version) using the app. 

I am unable to open LR -> Adobe Photoshop Beta, however, after doing the same procedure with that app. My workaroud is to generate the PSD using production Photoshop (24.7) and then opening it in Photoshop Beta from Lightroom. 

Reverting back to PS 24.6 will also fix the issue with files not opening in PS when using the "Edit In" function in Lightroom. 

same issue, I ended up downgrading to 24.6 to see if it works and so far things seem to be back to normal