hey im getting this problem, when i render a movie using the sequencer editor, some strange green light apears dont’ know why thnks for help
example in this link
and still no solution for that 
For us, we had to render as a separate process. Under Render Movie Settings, make sure “Use Separate Process” under the General section is checked.
Side note: If you have Steam running, it will record the popup message that will display while capturing the render.