Runtime Problems

How do I reset my session management settings?

Many people find session management very useful. However, sometimes session management can go astray, and do undesired things like remember your settings after your kid brother attacked your computer. If GNOME is properly installed, returning your settings to the default is easy.

First, exit completely out of X. If you are using session management, you should be able to use the Log out item of the Foot menu to exit. If that doesn't work, hold down the control and alt keys, and hit backspace. If that still doesn't work, and you are now looking at an XDM or GDM login prompt, switch to a text login (control-alt-F1 on many systems, consult your system documentation if you aren't sure, log in as a different user and use su in an xterm if you are really in a bind).

Then, to remove your settings, while you are out of X, remove the ~/.gnome/session file. The next time you start X, or the next time you log in from GDM, it should start you with the default window manager, panel, gmc and the help browser.

I started GNOME with session management, why am I just getting this grey screen (no panel, nothing)?

If you use session management, and it can't find a session, this is what it gets. First, have you tried resetting your session management settings (See above)? If this doesn't fix it, than gnome-session is having trouble finding the default.session file. In gnome-core versions 1.03 and later the file should be in $prefix/share/gnome. Prior to that it should be in $prefix/share. If the file is missing, you should probably reinstall gnome-core.

How do I tell session management what window manager to use?

This is a tougher question than it sounds, since the answer depends on which version of GNOME you are running. The easy answer is to use the Window Manager settings in control-center. If that doesn't work for you for some reason, here's how to do it.

In gnome-core version 1.03 and earlier, the window manager is selected by placing it in a file called default.wm. The system default for this file should be in either the $prefix/share/gnome or $prefix/share directories, whichever one has the file default.session.

A user-specific version of default.wm can be put in the ~/.gnome directory. The default.wm file should look like:

[Default]
WM=foo

Where foo should be replaced by the window manager you want. If you want to change the system default, you might also have to change the default.session file.

In gnome-core versions 1.04 and later, it is much easier. Set the environment variable WINDOW_MANAGER to the window manager you want, then start X. If that variable is not set, GNOME will run a script to make a good guess as to your window manager. You can also edit the ~/.gnome/default.wm file as in older versions.

Everything seems to be working, but most of my icons are just black squares, or random spots. How do I get my icons?

Most of GNOME's icons are PNG format graphic images, displayed via libpng and the Imlib graphics library. The trouble is, this part of Imlib seems to be very finicky, and it shows its displeasure by displaying garbage (the black squares are just cleaner garbage).

There are a few things that can cause this to happen. The most common problem is a bad, missing or confused libpng. If you have libpng version 1.0.2, assume it is bad. Only use versions 1.0.1, 1.0.3 or later. Missing is easy, if there is no file called "libpng.so" or "libpng.so.2", and you are on a system with dynamic libraries, it's missing, get a copy and install it. To see if it's confused, see if you have more than one copy of "libpng.so" or "libpng.so.2", if you do, remove them all and reinstall the right one.

Another possibility is one I have on one of my machines (A RedHat box with an AMD5x86 processor and egcs). If I use any optimization when I compile glib or imlib, I get the problem described (imlib uses the gmodule portion of glib to load the PNG code). Try compiling those two packages with no optimization switches on. That might fix it. As far as I can tell, this is a bug in my compiler, not in GNOME.

I have also received a report that the problem could occur from interference from some versions of ImageMagick. If you are at a loss, you might want to try removing or upgrading it.