This page tells you how to resolve problems in some applications if you receive strange/weird error messages or conditions.
You might also be interested in the FunnyApplicationErrorMessages wiki page. See also CommonErrors and ErrorMessages (for POSIX/libc error conditions).
If you do not get a drop-down menu when you click on a window's menu button, can't change the number of workspaces, and/or gnome-control-center says "the applet encountered an error" when you try to configure sawfish, it means that you have versions of sawfish and rep (and/or rep-gtk[-gnome]?) that don't like each other. For example, you have sawfish from debian woody (stable) but a rep from debian testing or unstable, even though these packages don't have an official conflict. Other symptoms include lines like "No such file or directory, sawfish/client" from the command line or in your .xsession-errors file.
GStreamer-ERROR **: No default scheduler name - do you have a registry ? aborting...
or
Failed to create the player: Couldn't initialize scheduler. Did you run gst-register?
Gnome 2 has moved to using the gstreamer suite for audio processing, including recording and playback.
The answer is to run the command "gst-register-0.8" as your normal user.
'Double registering:' If you have installed both gstreamer-0.8 and gstreamer-0.9, or have run gst-register-0.8 as 'both' root and yourself, delete the configuration files created by gstreamer at /root and your home directory, and run gst-register-0.8 (probably similar for 0.9) ONLY as root and try to start Rhythmbox again. (The configuration files are hidden.)
tar: Failed open to read on /dev/nrst0 <No such file or directory>
You're using a BSD-derived tar, but using GNU-tar options - it got confused and is trying to use the default tape drive device. See PortableProgramming? for tar option discussion.
find: paths must precede expression
Usage: find [path...] [expression]
The regular expression used matches files in the current path. Surround your expression with single or double quotes and it should work.
2 pages link to ApplicationErrorMessages: