How to understand & debug the blocked packages on OBS?

Couple of my packages are in blocked state in my private OBS. In UI it just show
downloading 1 dod packages
And in my /srv/obs/log/scheduler_x86_64.log, it shows below error

response from RPC dodfetch/openSUSE.orgebian:9.0/standard/x86_64 (http://my.obs.instance:5352/build/op...y=samba-common)
404 remote error: remote error remote error http //ftp.de.debian.org/debian/pool/main/s/samba/samba-common_4.5.16+dfsg-1+deb9u1_all.deb remote error Not Found


requesting 1 dod packages from openSUSE.orgebian:9.0/standard/x86_64