When attempting to deploy a project within the Jet Data Manager you encounter the following error message:
Error during deployment: An error occurred while saving a project to the database. An error occurred while updating. DataWarehouses Violation of PRIMARY KEY constraint 'PK_DataWarehouses'. Cannot insert duplicate key in object 'dbo.DataWarehouses'.
This error will only occur when you have multiple projects in the same project repository database. It is caused by having more than one data warehouse with the same name in the Jet Data Manager.
To resolve, right-click on your data warehouse instance within the Jet Data Manager and select 'Edit Data Warehouse'
In the window that opens up, change the value for the 'Name' of your data warehouse.
Once changed, click 'OK' to continue. You should now be able to deploy the project without issue.