How can I report a problem with LibreOffice?

Note: this is for further discussion of the answer given here: http://www.libreoffice.org/get-help/frequently-asked-questions/#reportbug

Since past few days, I am unable to open any libre office file, whether writer or spreadsheet or impress. What do I do. I searched for bug tracker but did not find anything
Padmini

If you’ve discovered a bug in LibreOffice, and want to report it to our quality assurance (QA) community, please see the bug tracker: https://bugs.documentfoundation.org/ When submitting a report, please check whether it affects the latest version of the software, and if so, please provide lots of detail in your report – operating system version, exact steps to reproduce the problem, and screenshot(s) if necessary.

can not print spread sheet in portrait mode. It will fit. Preview shows it in portrait, but printer shows it in landscape v5.4.1.2

since two days there s no way to see on display the single page, documents are always splitted in two pages displays; I also tried to reinstall but it was useless