ERROR ITMS-90596: "Invalid Bundle. The asset catalog at Payload"
I got the following when using Application Loader 3.7.1
I updated to 3.7.2 and it fixed the problem. So you may want to also make sure there's no new XCode versions.
Got this error when trying to upload Xcode 11 built ipa with old Application Loader.
But from Xcode 11 Application Loader is no longer included with Xcode.
When tried with the latest app submission approach using Transporter (https://apps.apple.com/in/app/transporter/id1450874784?mt=12), submission was successful.
Good Luck!
"I had two Xcodes on my Mac, Xcode 7.3 and 8.1. I made the archive using 8.1 but was uploading it with Xcode 7.3's Application Loader (3.5). Uploading with Xcode 8.1's Application Loader (3.6) resolved the issue for me".
https://forums.developer.apple.com/thread/63321