"ERROR: duplicate key violates unique constraint 'sampling_sites_identifier_sampling_site_key'"
Cause
You try to insert data in a table (here sampling_sites) and the identifier (here column identifier_sampling_site) of one or many rows already exists in the database.
Either somebody has already imported the same data set or somebody has at least used the same value in the identifier column (here identifier_sampling_site).
Solution
Check the already existing data in the database for that table. If your data were already imported, either you are happy with them or you need to contact the user who imported the data. Who this is can be found in the column created_by .
If you by chance build the same identifier for different data, consider to make your identifier more specific, e.g. by adding the country abbreviation as a prefix.
"ERROR: permission denied for view licenses" when deleting data
Together with "Error synchronizing with the database".
Cause
You tried to delete data in a view where you do not have the permission to do so.
Solution
To edit or delete data, please always use the views with suffix _import or _qa_rejected.