You need to use the correct link to report this. https://support.mozilla.org/en-US/kb/file-bug-report-or-feature-request-mozilla

If you are going report a bug, you need to give useful information as your post is rather minimal on information. It is a good idea to discuss your bug issues here first in case you can fix it or others may find a existing bug report in bugzilla. However if you think you still want to report a bug with (desktop) Firefox in Bugzilla then see https://bugzilla.mozilla.org/page.cgi?id=bug-writing.html https://support.mozilla.org/en-US/kb/contributors-guide-writing-good-bug