Regarding Log Parser Lizard, I am struggling to figure out how to change the regex in my log4netconfig.xml to match certain criteria for multi line log4net output. How do I specify in the regex that I want to match something on the second line of the output? The normal regex "\n" or "\r" does not seem to work

Currently, you can't match a regex in the second log line (for log4net input format). The parser for log4net works something like this: if the one line from a log file matches the regex, then that line is the beginning of a new record. If following lines are not matched by regex, they are added to the same record in [Full Message] filed. This approach works for most multi-line text log formats (including log4net) but it is not so flexible. We have plans to add more advanced Multi Line Regex Input format in future versions of the product, but we don’t have a set date.

In the meantime, you can try to use the SUBSTR function on [Full Message] field to extract data from the second line in a separate field.