[GIS] Adding new vertex using QGIS Vertex editor

Question

I'm having trouble adding new vertex using the QGIS3 Vertex Editor – I'm using
QGIS version 3.4.1-Madeira. I tried following the instructions provided in answer to Using QGIS vertex editor?.

The instructions stated:

QGIS 3.0 – Two options to add a new vertex:

1. Double-click on a segment to add a new vertex. The new vertex
   starts out selected and stuck to the cursor. Click a third time to
   place the vertex.

2. When hovering over a segment, there is an X in the middle of the
   segment. Click on the x to add a new vertex. The new vertex starts out
   selected and stuck to the cursor. Click a third time to place the
   vertex.

I've tried both of these with the following results:

1. double clicking on a segment seems to select and move an existing vertex,

and

2. hovering over a segment does not result in an x in the middle of the segment that I can click and move.

I have tried both options 1 and 2 above with snapping enabled and disabled and this doesn't seem to make any difference.

Any suggestions as to what I'm doing wrong?

Answer 1

To add a new vertex, hover the mouse over a line segment between two vertices. If your existing vertices are too close together, the vertex tool will tend to interact with the existing vertices instead of letting you create a new vertex.

Zoom in on the feature until the existing vertices are at least 1 cm apart. Once there's enough space between the vertices, the vertex tool can interact with the line segment instead of the existing vertices, and you should see a + sign when the mouse is over a line segment.