json decode won't work on string with array - php

Question

I'm trying to import something from an .xml file that I have no control over. Everything went fine until the content:encoded part.
I'm getting the xml like this to strip it of the CDATA Tags:
$xml_object = simplexml_load_file($file,'SimpleXMLElement', LIBXML_NOCDATA);
The looks like this, I'm trying to get rid of all the tags and just get the "contents.body" parts, but when I try to use json_decode($itemJson); it returns null. What should I do?
[{
"id": 34543,
"type": "0",
"order": 0,
"width": 100,
"height": 67.82337662337663,
"data": {
"areaMargin": 120,
"contentWidthOriginalPx": 760
},
"areas": [{
"id": 345654,
"order": 0,
"contents": [{
"type": "media",
"data": [{
"type": "width",
"value": "1540"
}, {
"type": "height",
"value": "1026"
}, {
"type": "videoSrc",
"value": ""
}, {
"type": "src",
"value": "https://link.com/1567819/98/eipej334.jpg"
}, {
"type": "alt",
"value": ""
}, {
"type": "mirror",
"value": "false"
}, {
"type": "zoom",
"value": "100"
}, {
"type": "rotate",
"value": "0"
}, {
"type": "positiony",
"value": "50"
}, {
"type": "positionx",
"value": "50"
}, {
"type": "url",
"value": ""
}, {
"type": "borderradius",
"value": "0"
}, {
"type": "sticky",
"value": "false"
}, {
"type": "metapic",
"value": "{\"id\":0,\"tags\":{}}"
}]
}],
"width": 100,
"height": 100,
"widthHeightRatioContent": 1.50097,
"widthHeightRatio": 1.47442
}]
}, {
"id": 2131656668,
"type": "0",
"order": 1,
"width": 100,
"height": 67.82337662337663,
"data": {
"areaMargin": 120,
"contentWidthOriginalPx": 760
},
"areas": [{
"id": 1650030480,
"order": 0,
"contents": [{
"type": "media",
"data": [{
"type": "width",
"value": "1540"
}, {
"type": "height",
"value": "1026"
}, {
"type": "videoSrc",
"value": ""
}, {
"type": "src",
"value": "https://links.com/jf/819/156722819/34/343.jpg"
}, {
"type": "alt",
"value": ""
}, {
"type": "mirror",
"value": "false"
}, {
"type": "zoom",
"value": "100"
}, {
"type": "rotate",
"value": "0"
}, {
"type": "positiony",
"value": "50"
}, {
"type": "positionx",
"value": "50"
}, {
"type": "url",
"value": ""
}, {
"type": "borderradius",
"value": "0"
}, {
"type": "sticky",
"value": "false"
}, {
"type": "metapic",
"value": "{\"id\":0,\"tags\":{}}"
}]
}],
"width": 100,
"height": 100,
"widthHeightRatioContent": 1.50097,
"widthHeightRatio": 1.47442
}]
}, {
"id": 1740427509,
"type": "0",
"order": 2,
"width": 100,
"height": 55,
"data": {
"areaMargin": 120,
"contentWidthOriginalPx": 760
},
"areas": [{
"id": 802708308,
"order": 0,
"contents": [{
"type": "body",
"data": [{
"type": "src",
"value": "<p>Lorem ipsum dolor sit amet.</p>"
}, {
"type": "html",
"value": "false"
}]
}],
"width": 100,
"height": 100,
"widthHeightRatioContent": 1.85874,
"widthHeightRatio": 1.81818
}]
}, {
"id": 79506641,
"type": "0",
"order": 3,
"width": 100,
"height": 55,
"data": {
"areaMargin": 120,
"contentWidthOriginalPx": 760
},
"areas": [{
"id": 28476702,
"order": 0,
"width": 100,
"height": 100,
"widthHeightRatioContent": 1.85874,
"widthHeightRatio": 1.81818,
"contents": [{
"type": "body",
"data": [{
"type": "src",
"value": "<p><span style="\
"font-weight:"
bold;\
"="
"><br></span></p><span style="\
"font-weight:"
bold;\
"="
">lorem upisn? </span>"
}, {
"type": "html",
"value": "false"
}]
}]
}]
}]