Why does my system bounce me back to the dtlogin screen when I try to log in?

PROBLEM DESCRIPTION

When you try to login to CDE after entering the correct login information from the login screen, you get bounced back to the login screen.

*This article requires remote server configuration. Administrator previlege may be required.

RESOLUTION

There are many possible causes for this problem. Here are some of the possible causes:

1. You do not have enough privilege to access/write on your own home directory
2. You do not have enough privilege to write on /dev/null
3. Invalid DISPLAY variable is set explicitly
4. Improper operation of the dtlogin login process

For each cause, you can try the following solutions:

You do not have enough privilege to access/write on your own home directory

Whether the user's home directory is on a local drive or NFS, a user must have write permission in it. Talk to the system administrator to set proper privilege(chmod 7**) in the home directory. 

You do not have enough privilege to write on /dev/null

Change permission on the /dev/null file to 666.

Invalid DISPLAY variable is set explicitly

Find out where the DISPLAY values is explicitly set and try removing it. DISPLAY value can be set explicitly and still use XDMCP without issue. However, it can easily lead to XDCMP failure if it is not set correctly.

Improper operation of the dtlogin login process.

Restart the dtlogin process or try reinstalling it. Before you do this, contact your system administrator.