Bubble on the wall

[designofsoul]

When do rendering appears bubbles on the wall as a light put on it.

[Fletch]

Low render settings = low quality light map = low quality rendering
Higher quality render settings = higher quality light map = higher quality rendering.

To fix:
Use Easy 09 render setting
or
Use higher quality rendering setting : Subject: Render Settings - the Best One
or
Use Sky portal on windows (see user manual)
or
Learn to create a better render setting for your scene: Subject: Easy 1-7 Photon Mapping and Final Gather (Biased)