SOLVED: Playback failed due to a fatal player error.

[TheDreadPirate]

Does the container have permission to write to where you mounted /cache?

Code:

[hls @ 0x55ca20fd11c0] Opening '/cache/transcodes/aafb203d653aeef9dad26c71c1b8f091-1.mp4' for writing^M
[hls @ 0x55ca20fd11c0] Failed to open segment 'aafb203d653aeef9dad26c71c1b8f091-1.mp4'^M
[out#0/hls @ 0x55ca1f629080] Could not write header (incorrect codec parameters ?): Permission denied^M