Error - user to assign task resolves as blank text

@dropsix .....Are there any attachments or detailed issue?

If your goal is to continue the workflow process even if the User column (which you're using to assign tasks) is blank then put assign task in Run If action and put condition that If User field in not empty then assign the task. 

Please provide detailed issue if that's not what you need else please mark this as solution if it works for you.

This solution isn't efficient when my task has a lot of actions within both outcomes. I don't want to repeat it once if one participant variable is blank. I have two participants, both set in variables earlier in the workflow. One variable is always populated, the other is not always populated. What can I do so the task still runs when one variable is blank?