Problem with lightning

Hi.

Im having some problems with the lightning in cycles. The scene dosent get any brighter, and the emisson object dosent shine up as it should. It just look greyish, and so is the scene. It gets brighter but in an of white ugly way. If I start a new project everything work as it should. Have anyone experienced this before? And if so; Do you know how to solve this?

Thank you

Please don’t double post.