Try giving permission to Lightroom folder under
/Users/[user name]/Library/Application Support/Adobe
Click on Finder and on the menu bar ( top side the of the screen) click on Go > Go to,folder
In the window type exactly ~/Library and click on Go
Open Application Support > Adobe and right click on Lightroom folder and select get info
Under sharing and permission Click on lock and unlock it
Click on + add your current user name and administrator if not added
Then give Read and Write permission for Admin, system, everyone and (your user name)
Click on gear icon and choose apply to enclosed item
Then Click on Lock
Launch Lightroom and check.
Thank you so much - I worked
Tak you for answering but I already tried that - I uninstalled the Nik-plug, but it still didn´t work.
Then I opened up another user and i worked ok - but it is not at good solution to have to switch user all the time...
The answer from Sam.am worked
I am glad to hear that : )
That worked for me! Thank you so much!