Dependencies (links) not rendered in gantt chart

I have some json for some tasks and links which looks correct to me but for some reason the dependencies (links) aren’t being rendered in the gantt chart. Below is the json for the tasks and links. Is there something wrong with the json which is causing the dependencies to not get rendered? Thanks.

{
“data”:[
{
“id”:2628,
“start_date”:“2018-12-04 00:00:00”,
“duration”:1,
“text”:“All SW Config Complete (OCC, ExaCC, BDCC, PaaS, Expansions, etc)”,
“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“taskStatus”:“NotStarted”,
“resource”:“Project Manager”,
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“open”:1,
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“action”:"",
“planned_start”:“2018-12-04 00:00:00”,
“planned_end”:“1970-12-31 00:00:00”,
“end_date”:“2018-12-05 00:00:00”,
“parent”:0
},
{
“id”:2629,
“start_date”:“2018-11-27 00:00:00”,
“duration”:1,
“text”:“Phase 0: PreSales”,
“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“variant”:"",
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“planned_end”:“1970-12-31 00:00:00”,
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},
{
“id”:2625,
“start_date”:“2018-11-27 00:00:00”,
“duration”:1,
“text”:“Test Task”,
“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“resource”:””,
“variant”:"",
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“planned_end”:“1970-12-31 00:00:00”,
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“end_date”:“2018-11-28 00:00:00”
},
{
“id”:2635,
“start_date”:“2018-11-27 00:00:00”,
“duration”:1,
“text”:“PCMA complete”,
“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“resource”:””,
“variant”:"",
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“end_date”:“2018-11-28 00:00:00”
},
{
“id”:2647,
“start_date”:“2018-11-27 00:00:00”,
“duration”:1,
“text”:“CA Form approved by PM”,
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“resource”:“Project Manager”,
“variant”:””,
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“planned_end”:“1970-12-31 00:00:00”,
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},
{
“id”:2644,
“start_date”:“2018-12-03 00:00:00”,
“duration”:45,
“text”:“Phase 6: Software Install & Configuration”,
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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},
{
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“start_date”:“2018-12-01 00:00:00”,
“duration”:18,
“text”:“Phase 4: Order Delivery (Build&Ship)”,
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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},
{
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“start_date”:“2018-12-08 00:00:00”,
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{
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“start_date”:“2018-11-30 00:00:00”,
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“text”:“Phase 3: HW Pre-Reqs completed & reviewed (PCMA, OEDA, FWR)”,
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},
{
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},
{
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{
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},
{
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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},
{
“id”:2660,
“start_date”:“2018-11-29 00:00:00”,
“duration”:13,
“text”:“Phase 2: Hardware Order (Internal Order)”,
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“planned_end”:“1970-12-31 00:00:00”,
“end_date”:“2018-12-12 00:00:00”,
“parent”:0
},
{
“id”:2627,
“start_date”:“2018-12-01 00:00:00”,
“duration”:1,
“text”:“IC Assigned”,
“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“resource”:””,
“variant”:"",
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“planned_end”:“1970-12-31 00:00:00”,
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“end_date”:“2018-12-02 00:00:00”
},
{
“id”:2632,
“start_date”:“2018-12-03 00:00:00”,
“duration”:9,
“text”:“Internal and External Kick Offs”,
“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“variant”:"",
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},
{
“id”:2639,
“start_date”:“2018-12-04 00:00:00”,
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“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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},
{
“id”:2636,
“start_date”:“2018-12-10 00:00:00”,
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“text”:“Confirm EXACC DB version”,
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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“end_date”:“2018-12-11 00:00:00”
},
{
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“start_date”:“2018-12-11 00:00:00”,
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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{
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},
{
“id”:2641,
“start_date”:“2018-12-08 00:00:00”,
“duration”:1,
“text”:“Primary Customer Contact Identified”,
“type”:“task”,
“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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},
{
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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},
{
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},
{
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“start_date”:“2018-12-09 00:00:00”,
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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},
{
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“description”:“Template to be used for the 21-Nov-2018 stakeholder demo “,
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{
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},
{
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},
{
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},
{
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{
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},
{
“id”:2633,
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},
{
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},
{
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},
{
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{
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{
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{
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{
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},
{
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}
],
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{
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{
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{
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{
“id”:427,
“source”:2638,
“target”:2626,
“lag”:null,
“type”:0
},
{
“id”:428,
“source”:2638,
“target”:2662,
“lag”:null,
“type”:0
},
{
“id”:429,
“source”:2642,
“target”:2634,
“lag”:null,
“type”:0
},
{
“id”:430,
“source”:2642,
“target”:2638,
“lag”:null,
“type”:0
},
{
“id”:431,
“source”:2642,
“target”:2649,
“lag”:null,
“type”:0
},
{
“id”:432,
“source”:2642,
“target”:2659,
“lag”:null,
“type”:0
},
{
“id”:433,
“source”:2642,
“target”:2626,
“lag”:null,
“type”:0
},
{
“id”:434,
“source”:2642,
“target”:2662,
“lag”:null,
“type”:0
},
{
“id”:435,
“source”:2656,
“target”:2642,
“lag”:null,
“type”:0
},
{
“id”:436,
“source”:2659,
“target”:2631,
“lag”:null,
“type”:0
}
]
}

Hello,
Please tell me which links (or links from which task to which) aren’t displayed? If I take your JSON config, there are 15 links. And all 15 links are displayed in the chart(you can count them manually if you delete the links one by one):
http://snippet.dhtmlx.com/ee9935d35
However, there is an unusual thing in your config. The link type is 0. If you didn’t specify that in the Gantt config that way, it should be "0".