Error sending file

[Mrgaton]

System.ArgumentException: The value cannot be null or empty. (Parameter 'mediaType')
at System.Net.Http.Headers.MediaTypeHeaderValue.CheckMediaTypeFormat(String mediaType, String parameterName)
at System.Net.Http.StringContent..ctor(String content, Encoding encoding, String mediaType)
at Discord.DiscordHttpClient.MakeMultipartFormDataContent(MessageProperties props)
at Discord.DiscordHttpClient.PostAsync(String endpoint, MessageProperties props)
at Discord.MessageExtensions.SendMessageAsync(DiscordClient client, UInt64 channelId, MessageProperties properties)
at Discord.MessageExtensions.SendFileAsync(DiscordClient client, UInt64 channelId, String fileName, Byte[] fileData, String message, Boolean tts)
at Discord.MinimalTextChannel.SendFileAsync(String fileName, Byte[] fileData, String message, Boolean tts)
at Discord.MinimalTextChannel.SendFile(String fileName, Byte[] fileData, String message, Boolean tts)

[Mrgaton]

Using net 7