What exceptions that cannot be explicitly checked have you encountered in your work experience?

In my experience with Java, I have encountered unchecked exceptions that do not require mandatory catching or declaration:

• NullPointerException — when attempting to access a method or field through null.
• ArrayIndexOutOfBoundsException — when accessing beyond array bounds.
• IllegalArgumentException — when passing an invalid argument to a method.
• NumberFormatException — when trying to convert a string to a number with an invalid format.

These exceptions typically indicate logical errors in the code and often require fixing rather than just handling.