HH1.17.2
Files 0.16.7
How to reproduce:
STEP1:
You are the owner of a space. Set it as follows

Add a new folder. Call it "Test"

STEP2
Sara Shuster is member of this space
She opens the space and she can see this

Apparently Sara cannot upload files. But she will try anyway

IT WORKS!
So this info
"This folder is empty.
Unfortunately you have no permission to upload/edit files."
was wrong!!