The composition job did not start because the combined size of the media sources passed to the composition is too large to process.
Due to fixed hardware constraints, Twilio is not able to compose all the media tracks specified in the composition create request. Check the maximum size on Known limitations
Please reduce the scope of the composition by excluding some of the sources to verity that they are below our maximum size. If not possible, please contact us and provide a description of the media files you are attempting to compose.