Hello,
In PVsyst 8 (replicated in 8.08, 8.10, 8.11 on multiple computers), there is a near shading bug when only some objects (not all) are selected to cast shadows, shading drops to zero when there should still be shading from the objects selected to cast shadows.
I've attached screenshots from an example project demonstrating the bug.
Shade scene:
Shading loss (zero):