https://github.com/openjdk/jdk/blob/11ad1733f8db3d8e868383fc9826963b9ffd620f/src/hotspot/share/cds/metaspaceShared.cpp#L802-L805

      aot_log_error(aot)("%s: %s", PENDING_EXCEPTION->klass()->external_name(),
                     java_lang_String::as_utf8_string(java_lang_Throwable::message(PENDING_EXCEPTION)));
      MetaspaceShared::writing_error(err_msg("Unexpected exception, use -Xlog:aot%s,exceptions=trace for detail",
 

The above code can crash if java_lang_Throwable::message(...) returns nullptr.