SharePoint Workflow SetState activity error when placed inside other activities

Question

I'm trying to add custom statuses to my SharePoint workflow but am encountering 'Error Occurred' when I try to set them. I've tried different ways of going about this.

For example in my SetState_MethodInvoking I've tried the following:

SetAssignmentState.State = 15;

This makes the workflow runtime throw:

System.ArgumentOutOfRangeException: Specified argument was out of the range of valid values.

and

((SetState)sender).State = 15;

This doesn't error, however the status is empty after this.

I've correctly added the statuses themselfs into the workflow definition within the MetaData tag:

<ExtendedStatusColumnValues>
        <StatusColumnValue>Hello World</StatusColumnValue>
</ExtendedStatusColumnValues>

After some trial and error I discovered that the error occurs because the SetState activity is nested within a while activity. I read that the correlation token should be set to that of the workflow, as it isn't task dependent. I've since tried creating a token just for this activity with different parents but I've not been able to find a combination that works.

I'd very much appreciate any advice about what might be the cause of this error when the activity is nested inside another.