The ssp_upgrade script does not handle errors from pkgadd(1M) very well. It does not exit when a pkgadd(1M) fails, and it displays an error that can be easily overlooked. This condition is more likely to happen when the SSP does not have enough disk space.
Workaround: Make sure enough disk space exists on the SSP before you attempt to upgrade or install SSP 3.1.1. The total size of the SSP packages is approximately 38.17 megabytes. The majority of the SSP files are installed in the /opt directory.