in the menu bar. Enter your Apple ID to clear any existing "stuck" certificates. : Ensure you are using an App-Specific Password Apple's ID Management if Two-Factor Authentication is enabled. Update Impactor

Because Cydia Impactor's creator (Saurik) only updates the tool sporadically, it frequently breaks when Apple changes its developer portal. If the latest version of Impactor still gives you the error, the community highly recommends moving to more actively maintained alternatives. The Apple Wiki 1. Sideloadly

Before diving into fixes, it is critical to identify why this happens. The root causes usually fall into one of three categories: