Activating a Sharepoint 2013 Workflow Feature

Question

I'll begin with the background of what I'm trying to accomplish. The system has a working workflow already, what I want to do is edit the workflow to meet some new requirements - so far I have only made a simple change to some text output to test.

I made the change through SharePoint Designer and then followed the instructions in the link below;

https://msdn.microsoft.com/en-us/library/office/jj819316.aspx

It worked as expected up until the activation of the feature. I have went through the usual steps clearing the cache etc but no matter what I can't seem to get past the error.

The workflow was exported from SP Designer as a WSP and uploaded to SharePoint.

Does anyone know of a way of forcing the activation of the feature?

Alternatively, advice on editing existing workflows would be appreciated

EDIT 13/08/15: Having followed Susan's advice I looked further into why the workflow wasn't updating via the publishing feature. I changed the site in designer to the actual sub site and made the changes there. This worked!

I thought that making the changes at the top level would automatically update all of the sites but this was not the case.

Answer 1

As per the edit in the OP. SharePoint Designer was making the changes but only to the specific site I was making the changes on.

The steps to creating the workflow I followed;

1. Create a 2013 Workflow in SP Designer 2013
2. Check for Errors, Save and Publish the workflow using the ribbon
3. Go to the specific site and run the workflow

As for how I distributed the workflow to all sites please consult;

Powershell - Publish Designer workflow on all sites