Environment HDRI Texture is Upside Down

Environment HDRI texture is upside down so the sky is reflecting and shadowing onto ceiling instead of the floor.
I’ve been trying to sort this out and I have a client waiting.
Any help would be appreciated, thank you.

We need a blend file for this.

I’ll see what I can do, it’s 250MB.

Since I’ve done much in the way of CAD work over the last 25 years, I thought it might be that as in CAD programs data can become corrupt rendering a file, at the least, problematic to work with, so why not also in Blender. I created a new file and copied all my models into it. As it turns out, my environment textures are positioned the way they should be. Thanks for your willingness to help me out. As it is, it looks like I may have dodged a bullet.

Glad it got sorted. Have to say that I haven’t had a corrupted file yet.

For future reference, you can just add some coordinate and mapping nodes into your HDRI, and negate the Z Scale value in the mapping node.

That was my initial thought, but copying to a new scene where it works suggests something else is going on.