I have an ArcGIS Online Hosted Feature Service.
I am trying to perform an updateDefinition and update the serviceDescription of a hostedFeatureService.
I am passing this as the payload to the rest service url
https://services.arcgis.com/abc/ArcGIS/rest/admin/services/CC_3_VMSData/FeatureServer/updateDefiniti...

This appears correct as per https://developers.arcgis.com/rest/services-reference/enterprise/update-definition-feature-service-....
But I get the following error
{
"error": {
"code": 400,
"message": "Unable to update feature service definition.",
"details": [
"Invalid definition for 'ServiceDescription'.",
"Exception has been thrown by the target of an invocation."
]
}
}
I can only set the serviceDescription to "", anything else returns the above message.
Any thoughts on how to overcome this?
Chris