As others have said the string is not a JSON string, so you will need to parse the string.
you have not said how you wish the output to look so i have parsed it to an array of objects in my example.
e.g.
[{"id":"f6332b85.359ec8","type":"inject","z":"bf9e1e33.030598","name":"","props":[{"p":"payload"}],"repeat":"","crontab":"","once":false,"onceDelay":0.1,"topic":"","payload":"","payloadType":"date","x":110,"y":100,"wires":[["cd12fe0d.b624d8"]]},{"id":"cd12fe0d.b624d8","type":"template","z":"bf9e1e33.030598","name":"","field":"payload","fieldType":"msg","format":"handlebars","syntax":"plain","template":"Channel.0.LineIndex=1\nChannel.0.LineIndex.1.Name=Privacybooth\nChannel.0.LineIndex.1.InCount=12\nChannel.0.LineIndex.1.OutCount=10\nChannel.0.LineIndex=2\nChannel.0.LineIndex.2.Name=EntryDoor\nChannel.0.LineIndex.2.InCount=4\nChannel.0.LineIndex.2.OutCount=3","output":"str","x":270,"y":100,"wires":[["dd838b61.413be","efaa07a0.5dd0e8"]]},{"id":"dd838b61.413be","type":"function","z":"bf9e1e33.030598","name":"","func":"msg.payload = msg.payload.split(\"\\n\");\nmsg.payload = msg.payload.reduce((acc, str) => {\n let parts = str.split(/\\.|=/);\n if(parts.length <= 4){\n acc[parts[3]-1] = {[parts[2]]:Number(parts[3]), [parts[0]]: Number(parts[1])};\n }else{\n acc[parts[3]-1][parts[4]] = isNaN(parseFloat(parts[5])) ? parts[5] : parseFloat(parts[5]);\n }\n return acc;\n},[])\nreturn msg;","outputs":1,"noerr":0,"initialize":"","finalize":"","libs":[],"x":440,"y":100,"wires":[["9efd2c72.cb6e88"]]},{"id":"efaa07a0.5dd0e8","type":"debug","z":"bf9e1e33.030598","name":"","active":false,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":460,"y":40,"wires":[]},{"id":"9efd2c72.cb6e88","type":"debug","z":"bf9e1e33.030598","name":"","active":true,"tosidebar":true,"console":false,"tostatus":false,"complete":"false","statusVal":"","statusType":"auto","x":620,"y":100,"wires":[]}]
msg.payload = msg.payload.split("\n");
msg.payload = msg.payload.reduce((acc, str) => {
let parts = str.split(/\.|=/);
if(parts.length <= 4){
acc[parts[3]-1] = {[parts[2]]:Number(parts[3]), [parts[0]]: Number(parts[1])};
}else{
acc[parts[3]-1][parts[4]] = isNaN(parseFloat(parts[5])) ? parts[5] : parseFloat(parts[5]);
}
return acc;
},[])
return msg;
output
[
{
"LineIndex": 1,
"Channel": 0,
"Name": "Privacybooth",
"InCount": 12,
"OutCount": 10
},
{
"LineIndex": 2,
"Channel": 0,
"Name": "EntryDoor",
"InCount": 4,
"OutCount": 3
}
]