[SR-Users] rtpengine upgrade fails

i build debian packages for rtpengine branch 3.3.0.0+0~mr3.4.1.0. after that i did 'apt-get dist-upgrade' and it failed like this: Setting up ngcp-rtpengine-daemon (3.3.0.0+0~mr3.4.1.0) ... Installing new version of config file /etc/init.d/ngcp-rtpengine-daemon ... Restarting RTP/media proxy: ngcp-rtpengine-daemonFATAL: Module xt_MEDIAPROXY not found. iptables: No chain/target/match by that name. ip6tables: No chain/target/match by that name. FAILED TO CREATE KERNEL TABLE 0, KERNEL FORWARDING DISABLED invoke-rc.d: initscript ngcp-rtpengine-daemon, action "restart" failed. dpkg: error processing ngcp-rtpengine-daemon (--configure): subprocess installed post-installation script returned error exit status 255 however, if i now run 'apt-get install ngcp-rtpengine-daemon', setting up ngcp-rtpengine-daemon succeeds and also packages that depended on it get installed fine: Reading package lists... Done Building dependency tree Reading state information... Done ngcp-rtpengine-daemon is already the newest version. 0 upgraded, 0 newly installed, 0 to remove and 0 not upgraded. 2 not fully installed or removed. After this operation, 0 B of additional disk space will be used. Do you want to continue [Y/n]? Setting up ngcp-rtpengine-daemon (3.3.0.0+0~mr3.4.1.0) ... Restarting RTP/media proxy: ngcp-rtpengine-daemon. Starting RTP/media proxy: ngcp-rtpengine-daemon already running. Setting up ngcp-rtpengine (3.3.0.0+0~mr3.4.1.0) ... any ideas why setting up ngcp-rtpengine-daemon fails with dist-upgrade? -- juha