Photoshop 2021 not flattening image?

[nzsky]

Hi all

I have auto update set in my Creative Cloud app so got the new 2021 photoshop and lost the older one, unexpectedly. I opened an image I started in PS 2021, flattened the 2 layers, saved as tiff, and when I open in Windows 10 photo viewer or in Topaz denoise only one layer displays even though only the flattened (and saved) image shows in PS layers.  If I export as jpeg the flattened image saves correctly. Also now topaz does not show as a plug-in. Any advice appreciated, thanks
Andrew

[Simon J.A. Simpson]

At the bottom of the 'Save as…' dialogue there's a tick-box which allows you to choose whether or not to save layers in a TIFF.  Is this ticked ?

[nzsky]

Yes I have layers, alpha channels, and ICC checked. I didn't explain the problem that well here's a better take:
I edited an image (in PS 2021), flattened two layers, saved as tiff, and when I open in any other app only the unmasked area of the top layer displays even though only the flattened (and saved) image shows in PS layers. If I export as jpeg the flattened image saves correctly.

[nzsky]

Unchecked 'save alpha channels' and seems to have resolved the problem...

[Simon J.A. Simpson]

There's always a box somewhere to catch us out !

 

[atiqursumon]

IMO, It is a tiff file which was never an issue until PS 2021. I guess it was the decision to save Alpha channels while saving - that was unregulated and the problem solved.

[edt]

same thing happened to me, PS would not Flatten or save some layered files. Long story short is that my late 2013 Mac Pro's GPU does not play with Big Sur and Capture One 21. Adobe customer service helped with the fix--had to go into PS Preferences/Performance and uncheck the box for "Use Graphic Processor" and that worked...