workflow - post on wall, A record with these values already exists. A duplicate record cannot be created. Select one or more unique values and try again

Hi.

I have several workflow that is stuck in a waiting status. When I open the workflow I get the following error: A record with these values already exists. A duplicate record cannot be created. Select one or more unique values and try again

The workflow is supposed to create a post on the users wall. Is there a way I can open for allowing duplicate posts?