When reading unclosed tag and hearing the instructor about this information, I was expecting to see two entries at the end of the day

<acpi>
<acpi/>

However, this is not the case, we just closed the "<acpi/>" and suddenly, it's working.

I also noticed the "<apic/>" and in the first glance, that sounded to me a typo, but it's not.

At the end of the day, if we just comment the line "<acpi>", it will also fix the issue, which is weird, once this should be the initial acpi entry.

<!-- <acpi> -->

Just to clarify, this can be a bit confusing if not explained correctly and with all the details. Definitely, it's not clear atm.