I'm trying to upload an update to an iOS app. Xcode goes through the usual dialogue and then immediately gets stuck on "Sending Analysis to App Store Connect..." Since the Xcode GUI doesn't provide any helpful information, I looked in Console. I can see Xcode completing an SSL handshake, then reporting that it "received viability advisory", followed by boringssl_context_handle_fatal_alert "level: fatal, description: bad record mac". After this it starts the SSL handshake again. It will cheerfully do this round and round forever without ever reporting a problem to the user. I found a similar post, which has one response about stripping bitcode from libraries (with no explanation as to why this would help), but my app does not include bitcode. I've updated to the latest version of Xcode incase there was some incompatibility, and rebuilt my app because, while that should be irrelevant to an SSL handshake, I'd expect someone to ask. Does anybody know what is going on and how to fix it?