Exports and printing
Excel with one sheet per tab, CSV, or print — always every row, never just the visible ones.
Open a report and press Export.
Excel
One .xlsx file with one sheet per tab, laid out as the tab is on screen:
the structure keeps each row's place in the tree in a Level column, the pivot keeps
its row and column headers and its totals.
Numbers arrive as numbers, so they can be summed in Excel without cleaning.
CSV
One file per tab. Written with a byte-order mark so Excel opens accented characters correctly rather than mangling them, which is the usual reason a CSV looks wrong on opening.
Print lays the report out for paper and PDF. Every open row is rendered first, including the ones scrolled out of view in a large grid (in a Structure tab, press Expand all first to include collapsed branches) — printing the visible screenful is a common failure in tools like this one, and it produces a document that looks complete and is not.
If the report hit its limit
When a report reads fewer work items than the source actually contains, the export says so, in the file. A spreadsheet that has quietly lost 4,000 rows is indistinguishable from a correct one once it has been emailed to somebody.
Browsers
Downloads are produced inside the app's frame. Chrome is the browser this has been tested in. If a download does not start in another browser, check whether it is blocking downloads from an embedded frame, and tell us — that is a bug worth a fix, not a limitation.