Crystal Reports Java Viewer slow without log4j properties file?

Hi, we recently had some performance issues with Crystal Reports Java Runtime (crjava-runtime_12.2.225). Especially large reports took over half an hour or more to generate. To examine this issue we configured a log4j.properties file. But we discovered that only having this properties file was already the solution for the performance issue. Even without logging at all (rootLogger=OFF) the same reports were generated in about a minute.

Does this mean the log4j.properties is a necessary part of the program?

Can this really be the cause of the delays in generating reports?

Best Regards,

Marc