500 Server Error on call

I am getting a 500 server error on a specific project (i think?)

My call:
https://app.asana.com/api/1.0/projects/744526852757229/tasks?opt_expand=this,this.subtasks%2B,this.followers

Result:
{
“errors”: [
{
“message”: “Oops! An unexpected error occurred while processing this request. The input may have contained something the server did not know how to handle. For more help, please contact api-support@asana.com and include the error phrase from this response.”,
“help”: “For more information on API status codes and how to handle them, read the docs on errors: https://asana.com/developers/documentation/getting-started/errors”,
“phrase”: “29 needy salmon stomp exactly”
}
]
}

Hi @Wayne_Pozzar, the API no longer supports accessing subtasks as a field on tasks. This may not be the root cause of the server error you encountered, but before we can begin diagnosing the issue we’ll need you to remove subtasks from your opt_fields.