Lines through my documents.
If it is striked-through, you may try
- Select All (Ctrl+A)
- Menu Format → Character → Font Effects tab →
- Strikethrough → select: (Without)
(I’ve noticed this behavior with LibreOffice 3.3.4, but it works fine with LibreOffice 3.6.3.)
If the line is a selectable object, try through the navigator F5