MED "Build Face" Problem, unselectable vertexes

Hello Guys,

I am currently trying to create some 3D Models by myself,
using MED. I know that the MED is not recommendet by most people,
and other editors like Blender etc. are much better, but at first I want to create 3D
Models for my Gamestudio Projects with the MED.

My big problem is that the Build Face Option does not work properly.
Sometimes, clicking on vertexes wont select the vertex, and then
I'm unable to build a face, since I cant select some vertexes. What am
I doing wrong?
The MED don't select the vertexes, but I want to build
my Model Poly by Poly, which I am currently not able to do..
The Vertex selection does not work both in the 3D- and 2D View.

Its not like that I cant select any vertexes to build a face, but some vertexes
wont get selected. Sometimes I even need to double click on a vertex to
select it, that could be a symptom.

I am using Windows 10 x64 (ignore the windows xp theme).
Here's a screenshot of the MED:

I have seen this happen when importing models. It could also happen if you create a model from scratch in MED. I believe it is caused by "groups." If you have vertices in different groups, then you can only select them when you are focused on that group. However, groups are only based on faces, not individual vertices, as far as I have been able to understand. Once a group is assigned, I'm not sure it can be removed, so this has been a strange problem for me in the past. One thing I've been able to do is to export to .obj, then re-import the model. The groups are all removed in that way, and you should be able to work on it again.

Hi Dooley,

thank you for your help! That really worked out.
Instead of exporting to obj and then reimport the model,
I've just endet up selecting every faces in triangle mode
and then arranged them all in one group, that helped too.

Kind regards,
freezernew

I figured there was a better way to do it!

There's a Group Merge command: https://i.gyazo.com/c0da15487b6ec9e649aa49302bb85db4.mp4

I know, but thank you all once again^^