"Appears to be corrupted" error when opening old iChat logs in Messages

When I try to open old iChat logs (circa 2005) with Messages on Catalina, I get the following error message: > The chat transcript “file name” could not be opened. > > This file appears to be corrupted and can’t be opened. If I try to open the same file in Visual Studio Code, I get the following: > The file is not displayed in the editor because it is either binary or uses an unsupported text encoding. Do you want to open it anyway? When I choose to open it anyway, I think I can make out pretty much all the text, but there's a whole bunch of gobbledygook in there that makes it a pain to read. Here's a sample: > typedstream��
@���NSArray��NSObject��
i����NSString
��
+AIM����������NSMutableArray���
/����InstantMessage����� Presentity��Person������� vp������NSDate��
d�A�X�m ؆����NSAttributedString����� you there?��iI
����NSDictionary������NSColor�����NSColor��
c
�ffff
�����NSBackgroundColor�����
��?t���?^�߃=���
�����NSFont�����NSFont���[28c]��Helvetica�
f��
������
I�������������anem�������A�Xә3�φ�������yup��
��������������
��?f��?���?=��
��������
�����������A�Xӷ G���������just checking in��
���������������A�XӷZ�?��������where are you? This post from 2011 on Apple's discussion forum appears to refer to a similar problem, but doesn't offer up any solution. Any way to open these in Messages to be able to read them normally?