Can't save entries with dynamic subfolder path in Matrix I have a Matrix field which contains several assets fields. Each has the dynamic subfolder path set to {owner.section.handle}, so I can reuse the Matrix in multiple sections, but keep the assets organized.
When I try to save an entry with an image, i get the error:

Craft\InvalidSubpathException
Could not resolve the subpath “{owner.section.handle}”
I figured it out -- I'll leave the question up in case anyone else runs into the issue. 

I had Assets fields in my Matrix, but I also had a SuperTable field in the Matrix which contained an image. That was the one causing the error. Changing the subfolder path to {owner.owner.section.handle} solved the problem.