Combining similar steps to both previous answers I did the following to have it work correctly: 1. Removed the current broken container 2. Open the terminal for the unraid host and ran : mkdir -p /mnt/user/appdata/semaphore chown -R 1001:1001 /mnt/user/appdata/semaphore chmod -R 755 /mnt/user/appdata/semaphore 3. Update the template variables: SEMAPHORE_DB_DIALECT sqlite SEMAPHORE_DB or SEMAPHORE_DB_HOST /etc/semaphore/database.sqlite (keeps the DB inside the mounted config path) Update as required SEMAPHORE_ADMIN, SEMAPHORE_ADMIN_PASSWORD, SEMAPHORE_ADMIN_NAME, SEMAPHORE_ADMIN_EMAIL SEMAPHORE_ACCESS_KEY_ENCRYPTION Generate a fresh one: head -c32 /dev/urandom | base64 Once started the setup proceeded normally and the container was operational. Apparently the combination of the new internal DB backend and the permissions were also required.