Comment 4 for bug 588181

> this issue happens just after stat-up inkscape, without any
> objects or any other operations.

Do you mean the eraser tool is active (instead of the select tool) after launching Inkscape, without actually clicking its toolbox button? Could something outside Inkscape send the keyboard shortcut (Shift+E) to activate it?

The red line (which disappears as soon as you release the mouse button) is AFAIU normal when using the eraser both in 'Delete' and 'Cut out' mode, with or without any objects present.