Hey, when I try to render a 20 min. long video using GPU acceleration, I get an error that says "An error occurred while creating the media file, and the reason for the error could not be determined." I am trying to render 720p video using the "MainConcept AVC/AAC (.mp4, .avc)" templates, but I cannot render even when the software recognizes my ATI Radeon HD 7950 GPU, and I have selected "Render using OpenCL if available." How can I solve this?