I have a customer who is trying to upgrade a 5.1.1 to a 5.1.2 on a two node cluster.
When they ran the upgrade they received error message "PRODUCT_NAME - entry not found in the string table."
then
"TITLE_MAIN - entry not found in the string table."
then
"TITLE_CAPTIONBAR - entry not found in the string table."
finally
received a Welcome screen with greeting "Welcome to the %P Setup program. This program will install %P on your computer".
They cancelled the install.

I have never seen this having run numerous upgrades myself. They are an administrator on the local machine.

Any suggestions would be welcome.