---
title: "Exceptions"
url: https://docs.catalyst.zoho.com/en/sdk/flutter/v2/exceptions/
description: "This help page lists the common exceptions that can occur in your Catalyst Android and iOS app executions built on Flutter SDK"
last_updated: 2024-09-13T05:40:11Z
service: All Services
type: general
related_links:
  - name: "Developer Tools"
    url: /en/getting-started/set-up-a-catalyst-project/developer-tools
---

# Exceptions

Exceptions are unexpected faulty behaviors that occur during the app execution. All errors and exceptions in Android or iOS apps built on Flutter SDK are handled by enumerations called `ZCatalystException`, defined in the Android SDK package.

If an exception occurs in your mobile app, the following Dart properties of the exception are returned:

* **`code`:** Unique identifier of the error
* **`errorMsg`:** General description about the error
* **`errorDetails`:** Additional information about the error
* **`originalException`:** The actual exception that was thrown

A list of common error codes thrown by the Catalyst Flutter SDK and their descriptions are given below:

<table class="content-table">
<thead>
<tr>
<th class="w30p">Error Codes</th>
<th class="w70p">Descriptions</th>
</tr>
</thead>
<tbody>
<tr>
<td><strong>INITIALIZATION_ERROR</strong></td>
<td>The SDK initialization failed</td>
</tr>
<tr>
<td><strong>LOGIN_ERROR</strong></td>
<td>The login process failed for the user</td>
</tr>
<tr>
<td><strong>LOGOUT_FAILED</strong></td>
<td>The logout process failed for the user</td>
</tr>
<tr>
<td><strong>TOKEN_FETCH_ERROR</strong></td>
<td>Failed to fetch the access token</td>
</tr>
<tr>
<td><strong>RESPONSE_PARSE_ERROR</strong></td>
<td>The received response is non-parseable</td>
</tr>
<tr>
<td><strong>NO_NETWORK_AVAILABLE</strong></td>
<td>Network connectivity is not available to make the API call</td>
</tr>
<tr>
<td><strong>API_FAILED</strong></td>
<td>The API invocation failed</td>
</tr>
<tr>
<td><strong>INVALID_DATA</strong></td>
<td>The data submitted is not of a valid type for the specific format</td>
</tr>
<tr>
<td><strong>FILE_SIZE_EXCEEDED</strong></td>
<td>The file size of an uploaded file exceeded the 100 MB file size limit</td>
</tr>
<tr>
<td><strong>FUNCTION_EXECUTION_ERROR</strong></td>
<td>Failed to execute the function</td>
</tr>
<tr>
<td><strong>JSON_EXCEPTION</strong></td>
<td>The body included in the request is not a valid JSON</td>
</tr>
<tr>
<td><strong>INVALID_REQUEST</strong></td>
<td>The request created is not valid</td>
</tr>
<tr>
<td><strong>INVALID_FILE_INPUT</strong></td>
<td>File submitted in the upload operation is not valid</td>
</tr>
<tr>
<td><strong>INTERNAL_ERROR</strong></td>
<td>An internal error occurred in the SDK</td>
</tr>
<tr>
<td><strong>INVALID_CONFIGURATION</strong></td>
<td>The SDK has not been initialized with the configuration required for the login. Reinitialize the SDK with the appropriate configuration for the login.</td>
</tr>
<tr>
<td><strong>CUSTOM_LOGIN_DISABLED</strong></td>
<td>The parameters required for third-party authentication could not be found. Make sure you have enabled third-party authentication for the project or re-download the property file.</td>
</tr>
</tbody>
</table>

### Exceptions in iOS Apps

If an error occurs in your iOS app, the following properties of the error are returned:

* `code`: Unique identifier of the error
* `message`: General description about the error
* `details`: Additional information about the error

A list of common error codes thrown by the Catalyst iOS SDK and their descriptions are given below:

<table class="content-table">
<thead>
<tr>
<th class="w30p">Error Codes</th>
<th class="w70p">Descriptions</th>
</tr>
</thead>
<tbody>
<tr>
<td><strong>INVALID_DATA</strong></td>
<td>Data is in an invalid format</td>
</tr>
<tr>
<td><strong>INTERNAL_ERROR</strong></td>
<td>Error occurred due to internal problems, servers, or something else</td>
</tr>
<tr>
<td><strong>RESPONSE_NIL</strong></td>
<td>No response was returned from the server</td>
</tr>
<tr>
<td><strong>TOKEN_FETCH_ERROR</strong></td>
<td>Failed to fetch the access token</td>
</tr>
<tr>
<td><strong>OAUTH_FETCH_ERROR</strong></td>
<td>Error occurred while fetching the OAUTH token</td>
</tr>
<tr>
<td><strong>UNABLE_TO_CONSTRUCT_URL</strong></td>
<td>Error occurred while constructing the URL</td>
</tr>
<tr>
<td><strong>PROCESSING_ERROR</strong></td>
<td>Error occurred while processing the data</td>
</tr>
<tr>
<td><strong>TYPECAST_ERROR</strong></td>
<td>Error occurred while type-casting the data</td>
</tr>
<tr>
<td><strong>NO_INTERNET_CONNECTION</strong></td>
<td>Device is not connected to the internet</td>
</tr>
<tr>
<td><strong>REQUEST_TIMEOUT</strong></td>
<td>Response from the server did not arrive on time</td>
</tr>
<tr>
<td><strong>NETWORK_CONNECTION_LOST</strong></td>
<td>Device has lost its connection with the Internet</td>
</tr>
<tr>
<td><strong>INITIALIZATION_ERROR</strong></td>
<td>Error occurred while initializing the SDK</td>
</tr>
<tr>
<td><strong>FUNCTION_EXECUTION_ERROR</strong></td>
<td>Error occurred while executing a function</td>
</tr>
<tr>
<td><strong>JSON_EXCEPTION</strong></td>
<td>Error occurred while parsing the JSON</td>
</tr>
</tbody>
</table>