This is a repeat of a question in the (restricted) Tridion Forum about the inability to delete a structure group. However, since it didn't get a proper answer or solution by the person reporting the question I am re-asking it here.
I am stuck with a structure group, which I can't delete either. It is not localized, only blueprinted to one other Publication and does not have any pages in it. The contents have been migrated from a presentation environment, perhaps an old target stuck somewhere?
Deleting it directly in the database is not an option. Any other solutions?
We came across similar issues at a customer. Our initial analysis was to examine the stored procedures that do the delete, and to see what constraints were enforced. On examining the data, we could see records that would not show up in the user interface, but which would prevent the deletion.
We raised a ticket with SDL Tridion customer support, and were able to agree with them which records should be modified in the database.
So that's the take-away from this: you aren't allowed to modify the database, but SDL Tridion customer support can sanction it, but only once they have checked that the changes are correct and necessary. Obviously, if you were to attempt to do such things without the co-operation of support, you'd end up with an unsupported system.