Mattermost server can't create files: permission denied

I have checked, double checked, triple checked that all permissions and ownership of files and directories are correct. Yet, despite being correct, the server logs are filled with permission denied errors when the server tries to create files. Many features (e.g. plugins, file uploads, etc) are rendered void or are disabled or completely missing, and I believe it is because it fails to modify necessary files. These problems occur despite having followed the tarball deployment documentation to a T. Any help is appreciated.

Figured out the issue: had a typo in the service file.