When I try to copy a survey I get the following database error:

Duplicate entry 'HhNReo7jElubjIf6' for key 'idx_survey_surveys_surveykey'

Tested version is 4.6.6.
To produce this error, I go to "Surveys", Mark a survey in the list by checking the box, selecting the button "Batch", choosing a category and then select the option "Copy", then I click on the button "Process".
Result is error number 1062 with the message shown above.
Can Europe produce this behaviour in your environment? If not, please let me know, and then I will send you access credentials for the affected environment.
Thank you very much for looking into this.
Kind regards, Andreas