# Errors from IFS

## ODP\_MISSING\_PRECONDITION

<figure><img src="/files/wNzDr5wF75F5n5mUSBZS" alt=""><figcaption></figcaption></figure>

This error indicates that the IFS API is expecting additional parameter(s) in request header.  Inspect the request header contents in Chrome inspect log and add required header attributes. Finding out what attribute is missing is solved by the "trial and error" method.

The error in this example occurred during Update-operation which requires if-match attribute. Read [here](/flow-ifs-cloud-development-guidelines/flow-development-with-odata/implementation/operation-specific-notes/update.md) more about solving this issue.

<figure><img src="/files/cgnpzxU8XtxvIfjPdLS0" alt=""><figcaption><p>Adding one header attribute </p></figcaption></figure>

### Adding several header attributes

In case more than one additional header attribute needs to be added, create a Flow table table(Name, Value) and  provide values and use in the machine step as in the example.

<figure><img src="/files/It2OsRCFE8WwFigvEzn3" alt=""><figcaption><p>Adding several custom header attributes to a table</p></figcaption></figure>

<figure><img src="/files/xbB4CvjWVLR0bsLZpLDD" alt=""><figcaption><p>Configure custom header attributes from a table</p></figcaption></figure>

## ODP\_DESERIALIZATION\_ERROR

```json
{"error":{"code":"ODP_DESERIALIZATION_ERROR","message":"Error while de-serializing contents."}}
```

Rest call header does not include "Content-Type" value "application-json" or body is not correctly in json format. Normally occurs when you call IFS outside flow apps (like Postman).&#x20;

## MI\_MODIFIED\_ERROR

To improve the response time, the IFS OData Provider caches the projection metadata once it is loaded from the database. During each call OData Provider validates the cached metadata version with that of the database. If the validation fails, the request will fail with HTTP response code 500 and the response body will contain the error code as MI\_MODIFIED\_ERROR. Then OData-Provider will invalidate the cached metadata, forcing it to be fetched from the database at the next request.

<figure><img src="/files/J5qgYEDahdKt5Ea0aKzg" alt=""><figcaption><p>Projection has been updated in database</p></figcaption></figure>

When a user gets this error response the OData-Provider expect the user to retry the same request again. Then OData-Provider will load the latest projection metadata from the database and serve the request accordingly.

{% hint style="info" %}
*Change request NPS-1333 created regarding this if OData connector could repeat the call automatically if this is error received from IFS.*
{% endhint %}

## ODP\_RESOURCE\_NOTFOUND

Error occurs when you execute Ready by Key -operation with an non-existent entity key.

<figure><img src="/files/P8g8fqmKqetXg8sSs0Gr" alt=""><figcaption></figcaption></figure>

## ODP\_NOT\_IMPLEMENTED

Error Indicates that API specification exists but implementation is missing. Select another operation.

<figure><img src="/files/MpaOega5gcxj7OmlwOhw" alt=""><figcaption><p>API not implmented buy IFS</p></figcaption></figure>


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