After click submit bottom I got the message

Error submitting filing electronically. Error reason: Employee street address is invalid or missing. It must contain an alpha character.

Then I clicked to view which employee's street address in invalid

It took different window then I got 

Gateway Timeout

The proxy server did not receive a timely response from the upstream server.

Reference #1.70fd017.1674673671.13809273

How do I find which employee's address invaild