Python Scrapy's ImagesPipeline not working

I have this in settings.py

ITEM_PIPELINES = {
 'scrapy.pipelines.images.ImagesPipeline': 1,
 'craigslist_tickets.pipelines.CraigslistTicketsPipeline': 2,
}
IMAGES_STORE = os.path.abspath(os.path.join(os.path.dirname( __file__ ), '..', 'images'))
DOWNLOADER_MIDDLEWARES = {
        'craigslist_tickets.crawlera_proxy_middleware.CrawleraProxyMiddleware': 200,
        'craigslist_tickets.retrymiddleware.Retry': 300
    }

And in items I also have

images = scrapy.Field()
image_urls = scrapy.Field()

This images folder also exists, I have confirmed. But I dont see images being downloaded and the images Item field is empty.

BTW, I can clearly see that image_urls have image links in it.

But I am getting error when Scrapy tries to download images.

Error downloading image from <GET https://iwebsite/00N0N_5x7aEwmjsQS_600x450.jpg> referred in <None>: 'X-Crawlera-Session'

I am using Crawlera proxies too.

Another hint: there is no folder named full inside images as I think it should be there.