Light problem

I get a weird lighting without any light sources, not even artificial lights. what do you think is the problem?

Hi there! Thanks for your reports! For now, we need you send your drs file to my e-mail address: and we will try our best to help you solve this issue.Best regards!

By the ways, Could you please tell me when it happen?Is it happen at the moment you open the drs file? Or after you add some material and do some operating?
Besides, Is it happen only in this project or exist in your other projects?Please let me know!

The problem solved…I think that it happened because I updated the version, but it is fine now. Thank you.