Can no longer run rviz

edit

Something happened and I can no longer run rviz. I get the following when I try to run it:

$ rosrun rviz rviz

find: invalid predicate `-L'

[rosrun] Couldn't find executable named rviz below /opt/ros/electric/stacks/visualization/rviz

find: invalid predicate `-H'

$ ls -l /opt/ros/electric/stacks/visualization/rviz/bin
total 4236
-rwxr-xr-x   1 root     root      1207114 Feb  6 14:22 image_view
-rwxr-xr-x   1 root     root       763727 Feb  6 14:22 marker_test
-rwxr-xr-x   1 root     root      1115605 Feb  6 14:22 rviz
-rwxr-xr-x   1 root     root       398799 Feb  6 14:22 send_grid_cells
-rwxr-xr-x   1 root     root       324022 Feb  6 14:22 send_images
-rwxr-xr-x   1 root     root       515215 Feb  6 14:22 send_lots_of_points

Any ideas?