Microsoft.Graph 5.75.0 graphServiceClient.Users[userId].Calendar.Events[recurringEventId].Instances.GetAsync() throwing Content type text/html does not have a factory registered to be parsed

[mghabin]

Hello,

Details:

• Multiple tenants affected.
• Multiple users affected.
• Microsoft.Graph 5.75.0
• Method used: graphServiceClient.Users[userId].Calendar.Events[recurringEventId].Instances.GetAsync()
• Calls made using App permissions (The tenants admins consented, and service principle is living in the customer tenant with right permissions)
• Issue started to happen in last month and we don't want this to grow.

Code used:

private readonly string defaultExpandExtendedProperties = $"singleValueExtendedProperties($filter=" +
     $"id eq '{ExtendedPropertyIds.A}'" +
     $"or id eq '{ExtendedPropertyIds.B}'" +
     $")";
var eventOccurrencesFilterParts = new List<string>
{
    $"singleValueExtendedProperties/Any(p: p/id eq '{ExtendedPropertyIds.A}' and p/value eq '{AValue}') " +
    $"or singleValueExtendedProperties/Any(p: p/id eq '{ExtendedPropertyIds.B}' and p/value eq '{BValue}')",
};

var occurrences = await graphServiceClient
    .Users[userId]
    .Calendar
    .Events[recurringEventId]
    .Instances
    .GetAsync(requestConfiguration =>
    {
        requestConfiguration.Headers.Add("Prefer", $"outlook.timezone=\"{timezone}\"");
        requestConfiguration.QueryParameters.Expand = [this.defaultExpandExtendedProperties];
        requestConfiguration.QueryParameters.StartDateTime = startUtc;
        requestConfiguration.QueryParameters.EndDateTime = endUtc;
        requestConfiguration.QueryParameters.Top = 50;
        requestConfiguration.QueryParameters.Filter = string.Join(" and ", eventOccurrencesFilterParts);
        requestConfiguration.QueryParameters.Select =
        [
            "id", "subject", "body", "bodyPreview", "start", "end", "organizer", "attendees",
            "singleValueExtendedProperties", "onlineMeeting", "originalStartTimeZone", "seriesMasterId", "type"
        ];
    });

Results in:

System.InvalidOperationException: Content type text/html does not have a factory registered to be parsed    at Microsoft.Kiota.Abstractions.Serialization.ParseNodeFactoryRegistry.GetRootParseNodeAsync(String contentType, Stream content, CancellationToken cancellationToken)    at Microsoft.Kiota.Abstractions.Serialization.ParseNodeProxyFactory.GetRootParseNodeAsync(String contentType, Stream content, CancellationToken cancellationToken)    at Microsoft.Kiota.Http.HttpClientLibrary.HttpClientRequestAdapter.GetRootParseNodeAsync(HttpResponseMessage response, CancellationToken cancellationToken)    at Microsoft.Kiota.Http.HttpClientLibrary.HttpClientRequestAdapter.ThrowIfFailedResponseAsync(HttpResponseMessage response, Dictionary`2 errorMapping, Activity activityForAttributes, CancellationToken cancellationToken)    at Microsoft.Kiota.Http.HttpClientLibrary.HttpClientRequestAdapter.SendAsync[ModelType](RequestInformation requestInfo, ParsableFactory`1 factory, Dictionary`2 errorMapping, CancellationToken cancellationToken)    at Microsoft.Kiota.Http.HttpClientLibrary.HttpClientRequestAdapter.SendAsync[ModelType](RequestInformation requestInfo, ParsableFactory`1 factory, Dictionary`2 errorMapping, CancellationToken cancellationToken)    at Microsoft.Graph.Users.Item.Calendar.Events.Item.Instances.InstancesRequestBuilder.GetAsync(Action`1 requestConfiguration, CancellationToken cancellationToken)    at **Reducted**

Please help us solving this as customers panics from this to grow.