holes in displaced wall

[G0M0]

Hello.
I have problem with some holes appearing in the solid wall after applying various combinations of displacement settings.
Below one example in two versions:

On this example I use 3d displacement (usually with one turbosmooth iteration beneath) but holes appears also with subdivision mode.
I tried many combinations of the rest parameters - there is always some holes.
I know it is related to the topology, but it is made in such a way to simulate smooth transition on the corners end edges (usual additional loops).
Is there some way to eliminate this bug completely?

[vlado]

How far is your scene from the coordinate system origin? Also, the the UVs and textures line up properly along the wall edges?

Best regards,
Vlado

[G0M0]

Here is the scene.
I've tried various uvs, even such with no uv seams visible through camera (simple pelt of visible polygons).