The above error may happen when doing the following in Enterprise Portal:
Navigation: Portal Administration -> Branding -> Define Headers or Define Footers (Add / View existing Value)
Add a New Value or Find An existing Value
Set Header ID: TEST1
You will get this message "An error has occurred that has stopped this transaction from continuing."
This message appears in Enterprise Portal due to 0 rows in PS_INSTALLATION Table. To fix this issue: Insert a row in PS_INSTALLATION table and restart the appservers.
The SQL I have used is as follows.
INSERT INTO PS_INSTALLATION
Tested this with Enterprise Portal 8.8 and PeopleTools 8.48.16