I tried to upload my latest build to iTunes Connect, but it shows the error below. This happened after I renewed my Developer account.
Here is the Application Loader Error Report
INFO: Web service received a server status of: HTTP/1.1 502 Bad Gateway
[2019-06-13 17:11:57 IST] <main> INFO: Web service response received: <html>
<head>
<title>502 Bad Gateway</title>
</head>
<body>
<h1>502 Bad Gateway</h1>
<p>Socks5ProtocolException("SOCKS5 mode failure: SocksError('Invalid SOCKS version. Expected 0x05, got 0x43',)",)</p>
</body>
</html>
[2019-06-13 17:11:57 IST] <main> ERROR: Communication error. Please use diagnostic mode to check connectivity.
[2019-06-13 17:11:57 IST] <main> DBG-X: Returning 1
I was able to find many problems like this and there can be any solution which might work for you.
To save time I would suggest you export the application Archive from Xcode's Organizer window (it saves this into a directory on the Desktop).
Then, from Xcode:
Xcode > Open Developer Tool > Application Loader
Also application loader is more descriptive for letting one know what's going on during the whole upload process.
Follow below reference which depicts same problem as yours :
App Store Connect Operation Error: Could not connect to Apple's web service
Unable to upload app to iTunes Connect - iTunes Store operation failed. Authentication timeout
Hope this helps.
Tip:- Problem was Proxy Settings
It ended up a network configuration issue. Go to Preferences > Network
Advanced > Proxies and make sure "Auto Proxy Discovery" and "Automatic Proxy Configuration" are checked but none of the other proxy options are checked. I had to uncheck "SOCKS Proxy" option to resolve the issue.