WorldServer - Impossible to delete a specific project type - error 'The project type could not be deleted'

When I try to remove/delete a Project Type from WorldServer, I get this error:

The project type could not be deleted

Please verify that:

1. The Project Type is no longer used in any Clients. Go to Management > User Setup > Clients, open each Client and in the Project Types section, remove the Project Type from the Selected Project Types list to the Available Project Types list. Click Save. Do this for each Client until you are sure that the Project Type is not associated with any Client anymore.
2. Once you have verified #1, if the Project Type still cannot be deleted, check if all projects that have been created with the Project Type you would like to delete have been not just been completed/cancelled but also archived, meaning that they are no longer visible under All Active Projects and under All Completed and canceled projects.

An easy way to find out whether active or completed/canceled projects created with the project type that you want to delete are still present in the User Interface is to:

1- In the Projects page, enable the column Project Types in your All active projects and also in your All Completed and Canceled Projects view
2- Search based on Project Type, entering the name of the Project Type you want to delete

You will probably find that one or more projects created with that Project Type are still visible in the User Interface. If those projects are active, they should be completed or canceled. Once they are completed or canceled, they will need to be archived before you can delete the Project Type used to created them. The archiving happens according to the Project Cleaner settings. If your Project Cleaner is set to archive projects that have been completed or canceled more than 30 days ago, your project will be archived accordingly. Once archived, those projects disappear from the User Interface, so your search will show no results. 

Once those completed or canceled projects have been archived, you will be able to delete the Project Type.

If, for some reasons, you cannot wait for the projects to be archived automatically via Project Cleaner, as a workaround, you could also delete those completed and canceled projects that are associated with the Project Type directly from the Worldserver Database. To delete/remove a project from the Database, please follow the instructions provided in this article:

WorldServer - How to delete Projects or Tasks from a Worldserver Database

Running the spdelete stored procedure in the Database (referred to in the article above) will not remove the project completely from the Database. It will move it from the Projects table to ArchivedProjects table, which is the same action the Project Cleaner does.

Please be aware that any changes in the Database are at your own risk. We recommend to involve a Database administrator to perform this action.

 

Projects using the Project Type to be deleted have not been archived yet or Project Type is still being used in a Client.

These articles might be relevant:

WorldServer - when trying to delete a Cost Model, I receive the error 'Not all of the Cost Models were deleted. The following objects still have dependencies."
Worldserver: when trying to delete a Cost Model, an internal error appears 'write permission denied'