Hello! Yes, exactly this issue. Right after placing of 3 spheres in 3 pentagramms and teleportation portal, on bottom level of dungeon I cant see anything. Is this a some common glitch, maybe exists some cure? Win 10 system.

First I would try the Caps Lock key.
It toggles free camera.
(you may have toggled it inadvertently, and the camera is now focused somewhere off the map.)

Failing that, I would try holding the Shift key and moving the mouse to the edge of the screen, to scroll the screen away from your character, release the Shift key and it should jump back to your character.
Holding the Shift Key also enables Free Cam.

Thanks, but i'm tryed to change graphical settings and its seems, turning on AlphaBit solving this issue completely. Instead of this appears ideal square pools, ha. Nice.