I've created a workflow and, in a determined point (2), it's possible to go back to a previous point (1). 

One of the conditions to access to point (1) is that determined field has to be empty (the field is pick list type). So, first time I access to (1), condition is reached. After that, value in the mentioned field changes. Once I arrive to point (2), I've configured as 'after' condition, to update mentioned field. But in this case I can't select 'empty', what I can do is to select 'none'.

So, I access to the loop (2), field value is changed to 'none', after that, I reach point (1), value isn't 'empty' and I can't continue with my workflow.

Is the problem clear enough? Is there any way to solve it?

Kind regards,

Macarena