How to delete records using worflows in MS Dynamics CRM 2013 online?

Hi, 

We have a business scenario in which we have to disble opportunity creation and qualify lead only to Account or Contact. I read a blog post which suggest a workaround that requires to delete the opportunity record newly created, based on a criteria. It was suggested in the blog to use the following CRM 2011 solution for the purpose:

http://crm2011workflowutils.codeplex.com/

But I am getting an error while importing (snaps attached). 

Is this because of the fact that I am trying to import it on CRM 2013 online or there's some other issue ? 

Please advise. 

Thanks, 
Fahad

Fahad Ali Shaikh