Unable to open topology file for vector map, grass 7, v.net

Question

I am introducing myself to Qgis using the FOSS4Glabs :

https://github.com/FOSS4GAcademy/GST102FOSS4GLabs/tree/master/Module%206%20Lab/QGIS%202.2

I am facing a problem during the module 6 Lab of the GST102 series. I am trying to construct a network data set using the v.net included in the GRASS Tools. I keep receiving the same error: "Unable to open topology file for vector map "

If I ignore the problem and continue the manipulation, I receive the following error message:

I tried to rebuild the topology using the v.build, but it didn't change a thing.

Does anyone have an idea about what I should investigate?

Answer 1

This is easy to fix.

Open the PERMANENT map set.

Then in the GRASS dialogue. Vector -> Develop Map -> Topology Management -> v.build.all

Then the old format layers will be converted to the new format and work correctly.