The type java.lang.Object cannot be resolved

This error message commonly occurs in Java when the compiler or IDE cannot find the definition of the java.lang.Object class.

This class is part of the Java standard library and is automatically imported into every Java program, so this error message usually indicates a problem with your Java installation or project configuration.

Here are some steps you can take to resolve this error:

1. Make sure that you have installed a valid JDK (Java Development Kit) on your system and that it is correctly configured in your project's build path or environment variables.

2. Check that your project's build path includes the standard Java libraries, which should contain the definition of java.lang.Object. In Eclipse, you can view and configure your build path by right-clicking on your project and selecting "Build Path > Configure Build Path...".

3. If you are using an IDE like Eclipse or IntelliJ, try cleaning your project and rebuilding it from scratch. This can sometimes resolve build errors caused by caching or stale files.

4. Check that your code does not contain any syntax errors or typos that could be causing the compiler to fail. Make sure that you are using the correct case and spelling for all class names and method calls.

If none of these steps resolve the error, you may need to seek additional help from a Java expert or community forum.