Logstash match add_field using dynamic field

Hey.
I am parsing a big log file with many different log line types.
What I am trying to do is to both pars parameters and keep a full line in a field called "text".
The problem is Logstash fails to create the pipeline when executed with my configuration.

This is a REALLY shortened version of my Logstash configuration file:

input {
file {
	path => "/opt/some/path/to/file.txt"
	start_position => "beginning"
    codec => multiline {
		pattern => "^%{TIMESTAMP_ISO8601}"
		negate => true
		what => "previous"
		max_lines => 1000
	}
	type => "aaa"
}
}
filter {
if [type] == "aaa" {
	grok {
		break_on_match => true
		match => {
			"message" => "%{TIMESTAMP_ISO8601:event_timestamp}%{SPACE}%{DATA:log_level}%{SPACE}\[%{DATA:host}\]%{SPACE}\[%{DATA:tenant}\]%{SPACE}\[%{DATA:java_class}\]%{SPACE}-%{SPACE}<Properties for the task %{DATA:task} has been set>"
			"path" => "%{GREEDYDATA:filename}"
			add_field => { "text" => "Properties for the task %{task} has been set" }
			add_tag => ["bbb"]
		}
	}
}
date {
	match => [ "event_timestamp", "YYYY-MM-dd HH:mm:ss.SSS" ]
	timezone => "Etc/GMT"
	locale => "en"
}
}
output {
elasticsearch {
	hosts => ["xxx", "xxy", "xxz"]
	index => "test"
	timeout => 120
	user => "xxxxx"
	password => "xxxxx"
}
}

The problem is the %{task} within the add_field which was parsed on the match above it.

The error i get is:

:exception=>"NameError"
:message=>"uninitialized constant LogStashCompilerLSCLGrammar::LogStash::Compiler::LSCL::AST:: Hash::ConfigurationError"

I will very much appreciate your help.
Thank you.