Lucy's blog

When creating a site collection based on the team site or document centre the feature ‘ReviewRouting’ is not enabled (yet). This results in ‘unknown task type’ in the error logs and 'Error Occurred' in the workflow status screen.

To fix this:
Enable the standard SharePoint feature ReviewRouting: Id = 02464C6A-9D07-4F30-BA04-E9035CF54392

Kudo’s to Stef for finding this.

Assigning a (workflow)task to a Group from code can be tricky, but this trick works:

SPGroup group = SPWeb.UserGroups[“groupname”];
SPFieldUserValue groupvalue = new SPFIeldUserValue(                  group.ParentWeb, group.ID, group.Name);
SPWorkflowTaskProperties taskProperties = new SPWorkflowTaskProperties();
 (Connect these taskproperties to the task to update)

taskProperties.AssignedTo = groupvalue.LookupValue;

To display these tasks in the task list the view 'Groups' has to be selected. they will not shop up in the 'My Tasks' view.