Both of these issues occur because you are using an old version of mIRC that is not compatible with newer versions of Windows. There is nothing you can change in older versions of mIRC to prevent the above issues, which were resolved in newer versions of mIRC.

Ideally, you should always use the latest version of mIRC, as it includes new features, bug fixes and security updates. If you are using an old script that only works with an old version of mIRC, I would highly recommend that you download the latest version of mIRC and find an alternative up-to-date script.