can't start new thread

Sorry, my English is not good, I will try to be as clear as possible

I used 3 servers to run my program, but there are still errors like error: can't start new thread

Here is my code

import hashlib
import datetime
import time, re
import newspaper
from newspaper import Article, Config, ArticleException
from lxml import etree

USER_AGENT = 'Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:78.0) Gecko/20100101 Firefox/78.0'
config = Config()
config.browser_user_agent = USER_AGENT
config.request_timeout = 25
config.number_threads = 1
config.thread_timeout_seconds = 5
config.keep_article_html = True


def spider_newspaper_information(build_url, website_name):
    start_time = time.time()
    web_paper = newspaper.build(url=build_url)
    print(web_paper.size())
    data_list = []
    for url in web_paper.article_urls():
        article = Article(url, config=config)
        try:
            article.download()
            time.sleep(1)
            article.parse()
        except ArticleException:
            continue
        if article.title == '':
            continue
        web_html = etree.HTML(article.html)
        web_time = ''
        if article.publish_date is None:
            try:
                web_time = web_html.xpath('//time/text()')[0]
            except:
                web_time = ''
        article_meta_data = article.meta_data
        video_url = []
        img_list = []
        for key, value in article_meta_data.items():
            if key == 'og':
                if 'video' in value.keys():
                    video_url.append(value['video'])
                if 'site_name' in value.keys():
                    if website_name == '':
                        website_name = value['site_name']
                if 'image' in value.keys():
                    img_list.append(value['image'])
        for img in article.imgs:
            if img in article.article_html:
                img_list.append({
                    'identifier': img,
                    'width': 960,
                    'height': 540})
        data = {
            'url': url,
            'source_url': article.source_url,
            'title': article.title,
            'top_img': article.top_img,
            'imgs': str(img_list),
            'movies': str(article.movies) if len(article.movies) != 0 else str(video_url),
            'text': article.text,
            'keywords': article.meta_keywords,
            'tags': list(article.tags),
            'authors': article.authors,
            'lang': article.meta_lang,
            'description': article.meta_description,
            'create_time': web_time if article.publish_date is None else article.publish_date.strftime("%Y-%m-%d %H:%M:%S"),
            'collection_time': datetime.datetime.now().strftime("%Y-%m-%d %H:%M:%S"),
            'website_name': website_name
        }
        print(data)
        data_list.append(data)
    return {
        'web_size': web_paper.size(),
        'data_list': data_list,
        'use_time': round(time.time() - start_time, 3)
    }

Is there any room for improvement? help...

Start with the spider_newspaper_information entry point and the newspaper.build call, reproducing the reported error with the shown Config values, especially number_threads=1. Check how newspaper.build creates threads and whether the displayed configuration reaches that call; done means identifying the cause and documenting a reproducible fix or required environment details.