Any reason you don't use 'tmsh load sys config' versus '/usr/libexec/bigpipe daol'? if there is configuration compatible issue, upgrade script may not be able to convert v10 configuration to v11, so /config/bigip*.conf will not be complete. v10 configuration is stored in /config/bigpipe. /usr/libexec/bigpipe daol is used to load v10 configuration and convert it to v11. thus, we will see error message while loading if had. tmsh load sys config is used to load v11 configuration which is in /config. in case if /config/bigip*.conf is not ready, tmsh load sys config may not be useful at that stage.