validation code errors

While attempting to validate code, I came up with these errors. Can anyone explain these validation errors?

# Line 119, Column 4: end tag for "ul" which is not finished.



✉

Most likely, you nested tags and closed them in the wrong order. For example

...

is not acceptable, as must be closed before

. Acceptable nesting is:

...

Another possibility is that you used an element which requires a child element that you did not include. Hence the parent element is "not finished", not complete. For instance, in HTML the element must contain a