So I've checked the forums, and I don't believe this specific error has been brought up. I apologize if it has.
I'm using the default AIM plug-in for Miranda 10.0.8, and it communicates with any other AIM protocols just fine EXCEPT for what appears to be vanilla AIM 22.214.171.124 (Which I believe is the most recent release as of April 2012)
Strangely enough, when my friend sends me an IM consisting of two sentences in one message, I get an invalid message error and the message does not display. I did a little testing and found that if I were to get two sentences separated by a period or question mark, such as "What? Why?" or "I'm fine. And you?" the message is dropped completely. Anyone else I communicate with who uses Pidgin or some other AIM-protocol using client as far as I know does not cause this issue. Additionally, commas do not cause the message to drop either.
When checking the log, the messages are always displayed as "Invalid Message", with nothing else. And as I stated before, the display is just the timestamp and no text at all. I checked my logs, and my friend has had AIM 126.96.36.199 for several months. As of July 19th, I started having the Invalid Message problem, which leads me to believe that it was my updating to Miranda 10.0.8.
Is there any other information needed to help try to reproduce/figure out the cause of this error?