There is a simple way to check if your cross-reference files are in error, or if your system objects are in error -- without waiting for crash. Type GO LICPGM, and then option 5 and select verify system objects. If everything is OK, you should receive the message "Task to prepare for install successfully completed."
You may want to also check out this IBM help information:
Verify system objects: When you select this option, the system verifies that the system directory entries include the user profiles needed by the installation process. If necessary, the QSECOFR and QLPINSTALL user profiles are added to the system distribution directory. This option will check to make sure the database cross-reference files that are needed to successfully install several licensed programs are not in error.