vRO 8 - Bind variable to workflow input issue

Hi,

I have a String variable that I want to bind to the input of a workflow, but when I try to select the variable at the input of the workflow it does not show the variable to select. I've tryed for many workflows that have a String as input variable, and for some workflows I can bind and for othes it does not show. For example, I cannot bind to any autogenerated workflow (autogenerated from a REST operation).

Is someone else having this issue?

vRO 8.

Thanks.