it´s nice to see there is an Adobe Community Professional helping in this forum.
As I have a 300MBit Internet connection I choose your last suggestion and uninstallen and installed Photosop new on my workstation. During the uninstalling I choose the option to delete all Settings to bes ure the new installation will be fresh without old settings.
BUT the problem that the export button kept beeing gray not black - and could not be activated is still so.
And when I try to open a picture from Lightroom with Photoshop then it opens in Photosop, but a window informs: Scriptwarning E/A-Fehler: Allgemeiner Photoshop-Fehler. Die Funktion steht in dieser Version von Photoshop möglicherweise nicht zur Verfügung. - keine weitere Information verfügbar
I / O error: General Photoshop error. The feature may not be available in this version of Photoshop. - no further information available
So I started to try your plan to make troubleshooting the card.
Therefore I did got to Help > System Info to see the Graphics Processor info. Then I got the Info:
Der Befehl Systeminformation konnet nicht verwendet werden, weil ein Programmfehler aufgetreten ist.
The system information command could not be used because a program error occurred.
By the way: copy paste is still not working.
My Dell workstation uses a NVIDIA Quadro M4000 graphic card.
As a user of Adobe products for more than 25 years I am not used to such problems.
As I need Photoshop every day I am not happy with these problems caused by the latest PS update.
Yay! I am glad to hear that you were able to get it taken care of.
Just a thought about updates: I turn off automatic updates, and I will only update as a brand new install of the software--and I always keep my old versions just in case I need to go backwards. When everything is working, then I make the switch to the newer version. I too have been using PS for over 25 years and in an every day production envioronment I need my tools to work.