“Terminate called without an active exception” is an error message you get in C++ programming, typically when an exception is thrown but not caught within its appropriate try/catch block.

Here’s a simplified way to explain what’s happening:

1. Exception Thrown: Your code runs into a problem (like trying to divide by zero) and throws an exception.
2. No Try-Catch Block: The reason you are getting this error is because the code that threw the error is not wrapped in a try/catch block. A try/catch block is used in various programming languages to handle exceptions (errors). However, if an exception is thrown and there is no try/catch block to handle it, the program doesn’t know what to do.
3. Termination: Because of this, terminate() function is called and your program ends abruptly, showing the error message.

Here is how you could resolve the issue:

“`cpp
try {
// Code that could throw an exception.
} catch (const std::exception& e) {
// Code to handle the exception.
}
“`

Remember to always handle exceptions in your code to prevent such errors.