What is blue dotted line between Columns A & B?

unable to print the entire spreadsheet

please attach your document or screenshot with this blue dotted line

Hello,

There should be two of these lines - one vertical and one horizontal. This signifies page breaks and is shown based upon (from menu) Tools->Options under LibreOfice Calc->Views whether the box is checked or not for Page breaks. Turning this on or off does not change the printing. Printing area is based on either Format->Page on Page tab using Paper Format or if you have a print range defined under Format->Print Ranges.