What have you done for trouble-shooting so far?
Restoring Preferences after making sure all customized presets like Actions, Patterns, Brushes etc. have been saved might be a good starting point:
Can you save as expected on an internal volume?
yes, i tried to restoring the preferences – no matter whats happened to the old stuff, i only want to solve this sh* … but nothing works …now it is that i can see PS could be running the mac OS "quit apps" dialogue-box but i can't quit it – and i can't see ps in the "command+tab" app-switcher if i try to restart the system – this process will be stopped by Photoshop …
the saving on internal-test is planned after restart … AND it works fast as hell … i did the 1st aid HD-repair on all my volumes but the psd-saving (with smart object) on the external drive isn't running.
regards & thanks!