Apple frequently updates how it handles app signing and developer accounts. Since Cydia Impactor hasn't seen a major public update in years, it often fails to "speak the language" of current Apple servers.

You can no longer use your standard Apple ID password in Cydia Impactor. Go to apple.com. Sign in and navigate to the section. Under App-Specific Passwords , click "Generate Password."

Developers later realized that the assertion should have been:

Operation returned HTTP status code 200 (OK) — indicates successful request/response cycle between Cydia Impactor client and target server. Scope: This report analyzes potential meanings of a 200 status in Cydia Impactor operations, common causes, diagnostic steps, and recommended fixes specific to typical Cydia Impactor workflows (sideloading .ipa via Apple ID, certificate signing, and device communication).