1.- Edit file log42net.config found within the following folder:
C:\Program Files\IBM\Domino\
or
C:\Program Files\IBM\Lotus\Domino
2.- Go to below section:
<appender name="RollingFileOnSize" type="log42net.Appender.RollingFileAppender">
and change the following line to DEBUG:
<threshold value="INFO" />
3.- Save the changes