normal map baking, strange lines around tiles, high poly to low

Hey there,

I am trying to bake my high poly model to a low poly objedct with normal map for export to collada and use in game engine.

I managed to bake from internal (what a cramp) and also from cycles.
The whole workflow is absolutely confusing.

In the end I came up with a model which looks ok between the vertices but has gaps between the lines. Check the image below:

the low poly cube without normal map looks like following:

How can i optimise my model. What is going on here? Why do i see those gaps?
Any Ideas? I am using Blender 2.79.
My blend file is attached…


cube_internal_001.blend (2.19 MB)

Maybe as explanation i would like to add the following info. The first image shows the baked texture map applied to the low poly model as normal map texture in blender internal.