Why am I seeing error message "Validation failed" after saving Sandbox module settings?

In the Sandbox module settings, clicking "Save changes" triggers an error message—"Validation failed"—which appears in the top-right corner of the screen.

This behavior is expected in MetaDefender Core versions prior to 5.7.1. It occurs because the content within the ChatGPT prompt exceeds the character limit supported by the Sandbox engine.

The issue has been resolved in MetaDefender Core version 5.7.1 and later.