The MissingResourceException is an unchecked runtime exception in Java that arises when a resource needed by a program is absent, and it doesn't require declaration in a method's throws clause. Common causes include missing resource files, undefined keys in resource files, or invalid Locale country or language codes. An example illustrates that attempting to retrieve a non-existent resource file results in this exception, which can be resolved by ensuring the resource exists with the correct name and location. Effective error management is crucial, and tools like Rollbar can automate error monitoring and triaging, providing real-time insights that facilitate confident code deployment.