Extension building is not built

[Yona-TYT]

I try to build a mail extension building at position (118,190), but it says "clear the tile before", however a city building was installed right there, so it must be a mistake.

To replicate, use "remove" on the building that is at (118,190) and then build a "post office" right there.
savegame:
https://www.mediafire.com/file/39ppp7ik0mipmo2/err_extender_post.sve/file

[prissi]

Somehow the fundations should have been never ever built at that level but one up. So the grid is broken in this area. Removing the building and saving/loading everything works fine, or putting an artificual slope there works too. This is rather a somewhat broken savegame.

[Dwachs]

One can replicate this by creating all these slopes with artificial slope tool, building houses, etc. So it seems that the grid-height handling has some bug.

[prissi]

The bug must be very old. When a building on a slope was deleted, the grid_hgts were not properly updated, leading to a wrong height (at the bottom) for the next building. I think I fixed this in r9125, although one has to be cautions. Also the ground will now use its own height if of type boden or fundation, overiding the old saved grid value.

[Yona-TYT]

It is curious that they have not detected it before. 

[prissi]

For this the original building must have been renovated. Still I am not sure how it could end up at a too low lever there in the first place.

[Yona-TYT]

- This is a bug in the script, you can remove this message.