可根据错误信息进行排查和调试。同时，可以通过以下代码示例进行调试和修复：

import boto3

client = boto3.client('stepfunctions')

response = client.start_execution(
    stateMachineArn='STATE_MACHINE_ARN',
    input='{...}',
)

execution_arn = response['executionArn']

execution_status = 'RUNNING'

while execution_status == 'RUNNING':
    response = client.describe_execution(
        executionArn=execution_arn
    )
    execution_status = response['status']

    if execution_status == 'FAILED':
        # 处理失败情况
        ...
    elif execution_status == 'SUCCEEDED':
        # 处理成功情况
        ...
    elif execution_status == 'TIMED_OUT':
        # 处理超时情况
        ...
    else:
        time.sleep(10)

其中，STATE_MACHINE_ARN为步函数的ARN，input为步函数的输入数据。以上代码会启动步函数，并通过循环轮询步函数的执行状态来进行处理。可以根据实际情况对失败、成功和超时等情况进行处理。