Hi Adam,
We have tried to reproduce this error and the only way we could get it is when we have inserted two same pages with same language inside same Ad.
If you could please verify if you have two or more same pages attached to same Ad by running this query on MonoX database:
SELECT
AdId, PageId, LanguageId
FROM
AdPage
GROUP
BY
AdId, PageId, LanguageId
HAVING
COUNT
(*) > 1
This query will return records that have AdId, PageId, LanguageId duplicates inside AdPage table. If this query returns anything, it means you have to delete one (or maybe even more) of those duplicates from AdPage table.
If query doesn't return anything then something else caused the problem.
Please let us know so we can continue investigating the problem.
Regards,
Ċ½eljko