Maniaplanet Forum

If you opens a saved replay and would like to edit it you can hit the lightbulb up left to recalculate shadows of this replay. In the vallley build 2013_07_04_11_32 it is not possible to select any shadow quality to recalculate.

You just can´t select any shadow quality, the buttons are grayed out.

I think this was already before, in Canyon, Storm and Stadium.
You have to modify the map a bit, e.g. add or delete a block.
And according to the Lightmap calculation thread, when there was no changes in the map, it's lightmap can only be replaced by a better quality lightmap.