Certain commands/actions within Carousel will require stored procedures to run against the database in order complete the action. By default these stored procedures can be viewed and edited within SQL Server Management Studio. They can be found under the Carousel50 Database > Programmability > and then Stored Procedures.
By default, the webui will need the procedures to be run under the dbo schema.
In the event that they are missing, or need to be altered, you can try rerunning the carousel script from the TRMS folder, if that doesn't work, you will need to find the specific "Create Procedure" line item and edit the text to include the "dbo." prefix in front of the stored procedure name.