Check your NAS
The NAS must provide Docker/containers, and Portainer CE must be connected to its local environment. Check the model and, especially on an older NAS, read its kernel with uname -r (the compatibility guide explains how). CUP’s tested minimum is Linux 3.10.108.
Recent NAS — kernel with getrandom: the image uses the kernel’s native function.
Older NAS — kernel without getrandom: from the tested 3.10.108 minimum, the image detects this and automatically enables the APR fallback for this case.
Below 3.10.108: do not install CUP until a compatible update or model check is available. Docker must also start, and the CPU architecture must be supported.

