When you remove a solution that the solution creates new SDK Message Processing Step each time you create a record (like Dynamics AutoNumbering) you receive a message that The component cannot be deleted because it is referenced by other components. In other words, the solution has dependencies that must be deleted before you remove the solution. To remove the dependencies of Dynamics AutoNumbering, follow these steps:
Open Advanced Find and select the record Auto Numbering. Click the Results Button. The displayed records are the Auto Numbering set up records (about 5-10 records if not less). Select all records and click: Delete Auto Numbering.
Once the records are deleted you can now remove the solution