Subs burning stopped working all of the sudden, they were working fine until now. I've tried everything I could think of to make them burn again without success. I also can not find any reason for which they've stopped working. They were working for one episode and stopped for the next one without me doing anything. The device profile I am using is Sony Bravia KDL (2012 models). The subs are properly auto-extracted when a new file is added, but the burning will not work.

What can I try to make them burn?