Umbraco Workflow is backwards compatible with Plumber data. However, with a new default namespace constituting a major breaking change any existing customization or extension needs to be updated.
To migrate from an Umbraco installation with an existing Plumber installation to Umbraco Workflow, follow these steps:
Uninstall Plumber and remove the /App_Plugins/Plumber folder.
Upgrade your project to Umbraco 10.
Install Umbraco Workflow 10. See the Installing Umbraco Workflow article.
Build the application.
SQL is the preferred database provider for production websites.
Uninstall Plumber and remove the /App_Plugins/Plumber folder.
Upgrade your project to Umbraco 10.
Make a copy of the Value column from the WorkflowSettings table.
Delete the WorkflowSettings table.
Update WorkflowTaskInstance table to allow null values in the GroupId column.
Install Umbraco Workflow 10. See the Installing Umbraco Workflow article.
Build the application.
Update the WorkflowSettings table to restore the previous data to the Value column.
All your existing workflow data and settings are not affected and will be available on your upgraded site.