STL question.“ There are no standard fluid cells in the computation."

[PoorWesley]

hello developers，
I recently set up a case that includes stl files and when I run it ，it reports this error:“ There are no standard fluid cells in the computation. Please verify geometry and mesh settings. If using an STL file to define the geometry, this may be due to normal vectors pointing in the wrong direction.”

htv_withwall_2023-12-11T154408.625563.zip (40.1 KB)
By the way , I don’t get an error when I set it up like this in other case. It’s really confused me.

[PoorWesley]

After trying, I found that changing the region range can solve this problem. Is that normal？

[onlyjus]

If your stl is just a box, you don’t need it. You can just define your geometry with the domain extents.