Posted by dellus on Aug 18, 2017; 8:33pm
URL: https://forum.librecad.org/Select-tool-not-working-tp5715255p5715256.html

When you are asked to choose a second edge you have used "select window" and when you thought to have selected a line by clicking on it you have instead defined the first edge of the window. So you are asked for the second, opposite edge.
In most cases you don't necessarily have to use the dedicated selection tools, but during an operation just click on the entities when asked for (close the selection with "enter"). Or pull up a window around them before the operation.
The parallel command (offset) doesn't work on all kind of objects, for instance not on ellipses, splines and blocks.