EC2 Amazon - Issue - We can't verify who created this file. Are you sure you want to open this file?

[HIEU DOAN]

When I install on EC2 Amazon, I have a problem with issue: "We can't verify who created this file. Are you sure you want to open this file?"
Sometime it's work correctly but almost time I got that issue.
Please help me with your idea or your experience.

This is the screen when it work correctly.

This is the screen when I got that issue

Thanks,
Hieu