What does a `java.lang.StackOverflowError` in JMeter typically indicate?

A `java.lang.StackOverflowError` in JMeter usually signifies that the Java Virtual Machine (JVM) has run out of stack space for a thread. This commonly happens with excessively deep recursive calls in your Java code, or in JMeter's context, it might occur in custom Java Request samplers or listener functions that enter an infinite or very deep recursive loop without a proper base case for termination.