I tried upgrading Confluence 5.9.7 to 6.15.1 via the installer on Windows Server 2012 R2 as per this support article, our old installation still uses the jTDS driver to connect to the database. The upgrade itself went without error, but when I launched the Confluence web interface it showed "The jTDS driver for Microsoft SQL Server is no longer supported. We were not able to automatically migrate your driver. To manually switch to the official Microsoft SQL Server JDBC driver, update the driver configuration in confluence.cfg.xml.".
I tried changing the driver as per this support article, here's where the problems start.
The MS SQL server on the same server as the Confluence installation uses the named instance "CONFLUENCE", the database name is "confluence" so I changed the line of "hibernate.connection.url" in the confluence.cfg.xml as per this Microsoft article to the following:
jdbc:sqlserver://localhost;instanceName=CONFLUENCE;databaseName=confluence
After that I reinstalled the service by running the service.bat in <install-directory>/bin, first with the parameter "remove", then with the parameter "install". This shows the following output:
Neither the JAVA_HOME nor the JRE_HOME environment variable is defined
Service will try to guess them from the registry.
Installing the service 'Confluence170316184538' ...
Using CATALINA_HOME: "C:\Program Files\Atlassian\Confluence"
Using CATALINA_BASE: "C:\Program Files\Atlassian\Confluence"
Ignoring JAVA_HOME: ""
Using JRE_HOME: ""
Warning: Neither 'server' nor 'client' jvm.dll was found at JRE_HOME.
Using JVM: "auto"
The service 'Confluence170316184538' has been installed.
When I try to start the service it immediately shuts down again, there are no new entries in the atlassian-confluence.log. The Windows event log shows an error 7024, source Service Control Manager, that error includes "Incorrect function".
I'd appreciate every help, I'm currently stuck in that state. Fortunately I cloned the VM where Confluence is installed so the production environment isn't affected, but I'm at a loss why the service doesn't even start anymore.
