# Response deserialization error

**URL:** <https://community.hubspot.com/t/response-deserialization-error/13735>\
**Category:** APIs & Integrations\
**Tags:** timeline-and-extensions-apis\
**Created:** [March 28, 2019, 12:52pm UTC](https://community.hubspot.com/t/response-deserialization-error/13735 "2019-03-28T12:52:02Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![jvdesu](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jvdesu/32/31851_2.png) [@jvdesu](https://community.hubspot.com/u/jvdesu)\
**Post date:** [March 28, 2019, 12:52pm UTC](https://community.hubspot.com/t/response-deserialization-error/13735/1 "2019-03-28T12:52:02Z")

</div>

I am attempting to display a card under contacts using the CRM Extensions API but getting a Response deserialization error. This is the JSON response of my Data fetch URI.

```auto
{
 "results":[{
 "objectId":1,
 "link":"",
 "title":"Engagement Details",
 "total_calls":0,
 "connected_calls":0,
 "total_notes":0,
 "total_emails":0
 }
]}

```

My Object Type

```auto
{
"id":98242,
"applicationId":191360,
"baseUris":[],
"dataFetchUri":"xxx",
"title":"ListingSpark Data",
"propertyDefinitions":[
{"dataType":"BOOLEAN","name":"total_calls","label":"Total Calls","dataType":"NUMERIC"},
{"dataType":"BOOLEAN","name":"connected_calls","label":"Connected Calls","dataType":"NUMERIC"},
{"dataType":"BOOLEAN","name":"total_notes","label":"Total Notes","dataType":"NUMERIC"},
{"dataType":"BOOLEAN","name":"total_emails","label":"Total Emails","dataType":"NUMERIC"}
],
"associatedHubSpotObjectTypes":["CONTACT"],
"associatedHubSpotObjectTypeProperties":{"CONTACT":["associatedObjectId","associatedObjectType"]}
}

```

---

<div class="post-metadata">

**Author:** ![jvdesu](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jvdesu/32/31851_2.png) [@jvdesu](https://community.hubspot.com/u/jvdesu)\
**Post date:** [April 1, 2019, 6:00am UTC](https://community.hubspot.com/t/response-deserialization-error/13735/2 "2019-04-01T06:00:34Z")

</div>

related question:

[https://community.hubspot.com/t5/APIs-Integrations/Hubspot-adding-quot-BOOLEAN-quot-dataType-to-propertyDefinitions/m-p/261430](https://community.hubspot.com/t5/APIs-Integrations/Hubspot-adding-quot-BOOLEAN-quot-dataType-to-propertyDefinitions/m-p/261430)

---

<div class="post-metadata">

**Author:** ![IsaacTakushi](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/isaactakushi/32/70387_2.png) [@IsaacTakushi](https://community.hubspot.com/u/IsaacTakushi)\
**Post date:** [April 1, 2019, 4:19pm UTC](https://community.hubspot.com/t/response-deserialization-error/13735/3 "2019-04-01T16:19:58Z")

</div>

Hey, @jvdesu.

Apologies for the delayed response. We endured [an outage](https://blog.hubspot.com/customers/a-note-on-the-march-28-outage) late last week which shifted our attention away from this forum.

I’m investigating your two posts more closely now.

---

<div class="post-metadata">

**Author:** ![IsaacTakushi](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/isaactakushi/32/70387_2.png) [@IsaacTakushi](https://community.hubspot.com/u/IsaacTakushi)\
**Post date:** [April 1, 2019, 5:54pm UTC](https://community.hubspot.com/t/response-deserialization-error/13735/4 "2019-04-01T17:54:17Z")

</div>

Hey, @jvdesu.

Thanks for bearing with me.

After reviewing the [CRM Extensions documentation](https://developers.hubspot.com/docs/methods/crm-extensions/crm-extensions-overview) and [related forum posts](https://community.hubspot.com/t5/APIs-Integrations/Response-deserialization-error-on-CRM-Extension/m-p/240863), I currently suspect the empty `"link" : ""` fields you return are causing the “Response deserialization” errors.

Per the`link` property’s description in [this article](https://developers.hubspot.com/docs/methods/crm-extensions/crm-extensions-overview), it is:

**The URI the user can follow to get more details about this object. This property is optional, but if not all objects have a link you should provide a value of `null`.**

I couldn’t find any requests that returned values, so I recommend trying to either:

- Replace the empty string`""` with`null`.
- Remove the`link` property from your app’s responses entirely.

Let me know if either of these work.

---

<div class="post-metadata">

**Author:** ![jvdesu](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jvdesu/32/31851_2.png) [@jvdesu](https://community.hubspot.com/u/jvdesu)\
**Post date:** [April 2, 2019, 2:21am UTC](https://community.hubspot.com/t/response-deserialization-error/13735/5 "2019-04-02T02:21:05Z")

</div>

No problem @IsaacTakushi!

I initially had no `link` field in the response but there was also no `objectId` in the response that time which also caused error.

I will try a response removing the `link` field only and let you know if it works!

Thank You!

---

<div class="post-metadata">

**Author:** ![jvdesu](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/jvdesu/32/31851_2.png) [@jvdesu](https://community.hubspot.com/u/jvdesu)\
**Post date:** [April 2, 2019, 10:07am UTC](https://community.hubspot.com/t/response-deserialization-error/13735/6 "2019-04-02T10:07:47Z")

</div>

Thank you @IsaacTakushi! I finally got to make it working.

I totally removed the `link` field and it fixed the error.

---

<div class="post-metadata">

**Author:** ![IsaacTakushi](https://d10pqhm3lwygmk.cloudfront.net/user_avatar/community.hubspot.com/isaactakushi/32/70387_2.png) [@IsaacTakushi](https://community.hubspot.com/u/IsaacTakushi)\
**Post date:** [April 2, 2019, 12:10pm UTC](https://community.hubspot.com/t/response-deserialization-error/13735/7 "2019-04-02T12:10:37Z")

</div>

Hey, @jvdesu.

Glad to hear it!