I got some warnings like this, but the display of my PDF seems ok, nothing wrong can be found in the report, I wonder what the problems are? I've read some answers here but still no idea, can anyone help me? Many thanks.
LaTeX (TeX, really) is very picky. A
\vbox is a vertical object, something like a page, if it complains it means it came up short to exactly fill the space or is too large. Ditto por
\hbox, a horizontal object typically a line.
If the problems are smallish (and not visible), you can ignore them. Often minor margin overruns can be fixed by rearranging a paragraph, use different wording, or such. The vertical complaints are often due to asking to place a figure or table where it doesn't fit, or asking for pages of the exact same length.
showframe(or, if you use
geometry, add the option
showframe) to visually check.