Upgrading PostgreSQL using QPI version 1.4 fails if Qlik Sense has been installed in a customer directory (such as D:\Sense or similar).
No supported existing Qlik Sense PostgreSQL database found
The installation logs indicate everything was detected correctly.
Resolution
Workaround:
Use QPI version 1.3.
Certain strings and characters cannot be used in the postgres password when using QPI 1.3, such as & $ " @ ^ §. Please change the password to a simpler one before the use of QPI and change it back right after the upgrade. Only the postgres user password needs to be changed, not qliksenserepository.
Fix Version:
Review the Release Notes of future QPI releases for details.