I think it's expecting a Wx::RichTextBuffer object, not an undefined scalar.

Update: Try: 

my $xml_handler = Wx::RichTextXMLHandler->new();
$xml_handler->LoadFile(
    $self->{rich_text_ctrl_1}->GetBuffer(),
    "output.xml",
);

[download]

In reply to Re: Wx::RichTextXMLHandler->LoadFile fails to load file into buffer. by ikegami
in thread Wx::RichTextXMLHandler->LoadFile fails to load file into buffer. by Steve_BZ

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