Hi! This is happening in development, right? This comes from the fact that edx-ace attempts to create the /edx folder. (This is caused by this horriiiiible line of code https://github.com/edx/edx-ace/blob/6b203f7280d038447328094649b58862f0abe794/edx_ace/channel/file.py#L20). In development, the user inside the docker container is not root so it does not have the rights to create this folder.
This error does not occur in production, as I verified, so I consider this a low priority issue. Would you be so kind as to create a github issue that links to this conversation? https://github.com/overhangio/tutor/issues/