Workflow to project a corridor feature to a referenced alignment

There is a workflow to project a corridor feature to a referenced alignment profile. I would like to project the bottom of a channel created by the corridor. The corridor is crated using the referenced alignment, trying to use the tool project profile to an element does not work. It shows that the referenced alignment is not editable. There is any other tool to do it or have something to do with the settings of the reference file. This workflow is working if the corridor and alignment are in the same file.

Thanks 

Nikolin