Login error SAP Landscape Management 3.0 SP13, Enterprise Edition (preconfigured solution)

I've launched and activated the solution "SAP Landscape Management 3.0 SP13, Enterprise Edition (preconfigured solution)"

I can connect to the login page, but unfortunately the login doesn't succeed.

It says: "User authentication failed"

I've tried unsuccessfully will all given Users (TRIALadmin, TRIALoperator, TRIALreadonly) with their corresponding passwords as of the getting started documentation.

Any Idea?