When creating segments, presets and playlists the JSON file is corrupt.
I have found large sections of spaces (4000 of them) and {“stop�:0}, which breaks the JSON.
At the start I was getting an invalid section with the following text in it.
win”:“Please refresh the page to see this newly saved command.”}}
I delete the first section, strip spaces and change the invalid character to " and upload via the edit screen and it works.