in reply to Re^2: DateTime::Format::Flexible; for Log Parse with multiple formatted lines
in thread DateTime::Format::Flexible; for Log Parse with multiple formatted lines

You need to use code tags, not only for the program code, but also for the the data that the program is supposed to read. In the text of your question, please use code tags to display:
Mon Feb 20 09:31:25 2017 [INFO] [AGENTEXEC] Error Description.
code tags also put things into a fixed width font. Your program is unable to parse this line:
2017-02-20T09:30:53.177000 20[] 0000000000000000 Error Description

In Perl, it is possible to define a file that is contained within the program code itself! This is called a DATA segment. A simple example:

#!/usr/bin/perl use strict; use warnings; while (<DATA>) { print; } __DATA__ Some example lines that could be in a file
The __DATA__ segment is a pre-opened file handle. There are ways to put multiple input files within the code, but a DATA segment for a single file is the most often used.

It is not clear to me what the desired output is. Please include an example of that in your post.