Use a program like PKzip. Just zip the file. Now, change the zip to aia. Just rename the file. That might work. Be aware that aia files are compressed zip files with aia in the extension instead of zip.
Did that work?
AI2 can not handle source plus assets larger than 5Mb. It is a firm limit. When users exceed that limit, they have issues like you experienced. Hope you are up and running.
Regards,
Steve