"Effect Mirror" not working on imported geometry

[MouseOver]

Hi

When Applying the "Effect Mirror" on my imported ground, nothing gets show. I think it flips weirdly my geometry, but i dont understand how or why. It is a flat plane
I added two screens, one with and the other without the "Effect Mirror". how to make this imported geometry reflect properly?

thanks!

[MouseOver]

*the simple mirror works, the blurred one, not

[Götz_B]

Hi,

did you solve your problem?
Seems to be related to the rotation and scaling of your geometry.
Check the attached scene.

Götz