Encountering JavaScript TypeErrors is a common issue for developers, especially after recent deployments, due to the diversity of situations they encompass and the variety of exception messages across different browsers and languages. These errors often arise when operations are attempted on values of unexpected types and can manifest during code refactoring when a function used elsewhere becomes problematic. Two prevalent cases include trying to access properties of undefined or null references and calling non-existent object methods or properties, with error messages varying by browser and language. In production environments, identifying and resolving these errors can be challenging due to the noise created by diverse visitor browsers. Utilizing tools like Rollbar can help manage this complexity by effectively grouping similar errors across different languages and browsers, reducing noise, and providing a clear, actionable view of errors to facilitate quick resolution.