Are you saving locally or across a network?
Can you reproduce the issue with the layered file on another machine?
What have you done for general trouble-shooting so far (trashing prefs by keeping command-alt-shift/ctrl-alt-shift pressed while starting Photoshop after making sure all customized presets like Actions, Patterns, Brushes etc. have been saved and making a note of the Preferences you’ve changed, 3rd party plug-ins deactivation, system maintenance, cleaning caches, verifying the disks, font validation, etc.)?
What is the Photoshop > Preferences > File Handling > Maximize PSD and PSB File Compatibility-setting?
I've used PS for several years without a problem with .psd/.psb files, but I'm questioning whether it's smart to save important CS6 work using this format.
So far I see no reason to question the validity of the file formats.
Thanks for the quick reply, CP
FYI, the file is a photographic panorama based on several .CR2 photos taken in July, 2012 and processed in CS5's camera RAW/Photoshop. Beyond the metadata, here are no fonts or text in the file.
1. I changed Maximize ...File Capability from "Never" to "Always" and the flattened file saved and loaded OK, though I can't figure why given Adobe's description of this option. "If you work with PSD and PSB files in older versions of Photoshop or applications that don’t support layers, you can add a flattened version of the image to the saved file...". The file saved in this manner is ~8% larger and is not my preference as a routine since I've TB's of photo files. By the way, out of thousands of .psd/.psb files, the one being discussed is the first to give me the error.
2. I've tried saving/reloading the file on another computer with Win XP Sp3/CS5...again with Maximize Capability OFF. Same problem. Turn ON Maximize Capability and it works. As with the Win 8 machine, Bridge could neither create a thumbnail or read Metadata.
3. I've purged the Bridge Cache, made sure there were no old PS page files, reset PS preferences, and disabled my 2 plugins with no change in the problem. Windows and Adobe progs are all updated. Saving to a different HDD has no effect.
The problem occurs on 2 computers (Win XP/Win 8), two versioins of Photoshop (CS5/CS6), and "Maximize" On/Off togles the problem. My guess it is a bug in PSD processing routines.
If I can't find a fix, will keep with Maximize ON and deal with the larger files that result...the cost of insurance, I suppose.