While building the concrete structure 3D model from Architecture objects (walls, columns, beams, slabs, staircases), when moving on to next levels, we realized that some of our beams, walls or slabs from earlier got subtracted -1 in the Floor manager.

Meaning that a slab which had the height set earlier from the "Top level of 1st floor" to the "Bottom level of 2nd floor", is now defined as from the "Bottom level of 1st floor" to the "Top level of 1st floor". First snapshot attached, where two parts of slabs became a whole floor in height! This is very irritating, when the slab needs to be adjusted for the 5th time in a week.

The reason why this keeps happening is beyond us. All we have to do is change these two defined floors to the right height and the slab or beam gets reset to the right position.

Also an error message keeps popping up with "Incorrect 3D data in drawing file XXXX. This can cause display problems." Well the problem is not in our display, cutting a view also confirms that the slab moved down in the floor manager list.

We suspect the "Change Arch. Properties" function changes the levels, but we are not sure, since it never happens when we are on the layer, only if we leave the layer unmodified for a while.