OK!
My aia size is 25.6 MB.
It seems not too big.
I have been check the previous chat of someone's feedback.
His aia file size is 38.x, it's more big than me right?
HTTP ERROR 500 problem - MIT App Inventor Help - MIT App Inventor Community
And also when I want to import the backup *.aia now.
It can't work, but it was worked previously.
So how can I do to fix it?
Could you please give me a advice?
Thanks a lot!!