To diagnose common problems that can arise when integrating a login application, the log file is very useful. The logfile is normally located in a directory called log in the instance's spool directory. The file name is usually nevislogrend.log. Logging is configured through the log4j.xml configuration file. To get the full nevisLogRend trace, set the severity of ch.nevis.logrend to DEBUG:
<category name="ch.nevis.logrend"><priority value="DEBUG"/></category>
Make sure to only set the severity to DEBUG if you really need it, for it will create a lot of output. Do not forget to set the severity back once you have finished the analysis of the log file.