qgis - How do I set mmqgis create grid options?

I am having a puzzle about using mmqgis create vector layer option. I want to use UTM CSR

this are my options. I want a grid of 20,000 meters in the east and north axis. Nevertheless i have an error screen stating: "invalid width/height 6.0/6.0". As I understand my settings I should have 6 lines separated by 20,000 meters Am I understanding this in the wrong way? Thanks in advance

Answer

Without checking, I would interpret to options as follows:

• left x: min x


• width: width of the complete grid, therefore ... min x + width = max x


• h spacing: width of one cell

same for the second dimension