openni_launch fails to start on ROS hydro

edit

I'm using ROS Hydro on Ubuntu 12.04 on a Roomba 4400 base. I've been using

roslaunch openni_launch openni.launch

to launch openni. The last time i successfully launched openni was today( a few hours before this post). But now i receive the following error when i try to launch openni or any other command which uses kinect ( e.g. roslaunch turtlebot_follower follower.launch) :

 terminate called after throwing an instance of 'openni_wrapper::OpenNIException'

  what():  unsigned int openni_wrapper::OpenNIDriver::updateDeviceList() @ /tmp/buildd/ros-hydro-openni-camera-1.9.2-0precise-20150515-0253/src/openni_driver.cpp @ 125 : enumerating image nodes failed. Reason: One or more of the following nodes could not be enumerated:

Image: PrimeSense/SensorV2/5.1.0.41: Got a timeout while waiting for a network command to complete!

[FATAL] [1462534504.287888196]: Service call failed!
[FATAL] [1462534504.288046458]: Service call failed!
[FATAL] [1462534504.288046461]: Service call failed!
[FATAL] [1462534504.288079748]: Service call failed!
[FATAL] [1462534504.288330007]: Service call failed!
[FATAL] [1462534504.288357209]: Service call failed!
[FATAL] [1462534504.288403796]: Service call failed!
[FATAL] [1462534504.288477609]: Service call failed!
[FATAL] [1462534504.288604595]: Service call failed!
[FATAL] [1462534504.288768839]: Service call failed!
[FATAL] [1462534504.288772040]: Service call failed!
[FATAL] [1462534504.288905728]: Service call failed!
[FATAL] [1462534504.288905732]: Service call failed!
[FATAL] [1462534504.289059881]: Service call failed!
[FATAL] [1462534504.289899319]: Service call failed!
[FATAL] [1462534504.290088786]: Service call failed!
[camera/camera_nodelet_manager-2] process has died [pid 6531, exit code -6, cmd /opt/ros/hydro/lib/nodelet/nodelet manager __name:=camera_nodelet_manager __log:=/home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-camera_nodelet_manager-2.log].
log file: /home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-camera_nodelet_manager-2*.log
[camera/debayer-4] process has died [pid 6569, exit code 255, cmd /opt/ros/hydro/lib/nodelet/nodelet load image_proc/debayer camera_nodelet_manager --no-bond image_raw:=rgb/image_raw image_mono:=rgb/image_mono image_color:=rgb/image_color __name:=debayer __log:=/home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-debayer-4.log].
log file: /home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-debayer-4*.log
[camera/rectify_mono-5] process has died [pid 6583, exit code 255, cmd /opt/ros/hydro/lib/nodelet/nodelet load image_proc/rectify camera_nodelet_manager --no-bond image_mono:=rgb/image_mono image_rect:=rgb/image_rect_mono __name:=rectify_mono __log:=/home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-rectify_mono-5.log].
log file: /home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-rectify_mono-5*.log
[camera/rectify_color-6] process has died [pid 6597, exit code 255, cmd /opt/ros/hydro/lib/nodelet/nodelet load image_proc/rectify camera_nodelet_manager --no-bond image_mono:=rgb/image_color image_rect:=rgb/image_rect_color __name:=rectify_color __log:=/home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-rectify_color-6.log].
log file: /home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-rectify_color-6*.log
[camera/depth_metric_rect-9] process has died [pid 6639, exit code 255, cmd /opt/ros/hydro/lib/nodelet/nodelet load depth_image_proc/convert_metric camera_nodelet_manager --no-bond image_raw:=depth/image_rect_raw image:=depth/image_rect __name:=depth_metric_rect __log:=/home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-depth_metric_rect-9.log].
log file: /home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-depth_metric_rect-9*.log
[camera/points_xyzrgb_sw_registered-13] process has died [pid 6695, exit code 255, cmd /opt/ros/hydro/lib/nodelet/nodelet load depth_image_proc/point_cloud_xyzrgb camera_nodelet_manager --no-bond rgb/image_rect_color:=rgb/image_rect_color rgb/camera_info:=rgb/camera_info depth_registered/image_rect:=depth_registered/sw_registered/image_rect_raw depth_registered/points:=depth_registered/points __name:=points_xyzrgb_sw_registered __log:=/home/asaad/.ros/log/8593b2ce-137e-11e6-b5d3-90004ecd8dc9/camera-points_xyzrgb_sw_registered-13.log].
log file: /home ...