Elasticsearch Scroll API error: RequestError(400, 'ElasticsearchIllegalArgumentException[Failed to decode scrollId])

I'm currently using Elasticsearch 1.3.4.

When using the scroll API via the Python ES Client (taken from this example:

page = es.search(
    index = INDEX_NAME,
    scroll = '1m',
    size = 1000,
    body={"query": {"match_all": {}}})
    sid = page['_scroll_id']
    scroll_size = page['hits']['total']

    # Start scrolling

    print( "Scrolling...")
    while (scroll_size > 0):


        print("Page: ",count)
        page = es.scroll(scroll_id = sid, scroll = '10m')
        # Update the scroll ID
        sid = page['_scroll_id']

        for hit in page['hits']['hits']:
            #some code processing here

I got the following error:

elasticsearch.exceptions.RequestError: RequestError(400, 'ElasticsearchIllegalArgumentException[Failed to decode scrollId]; nested: IOException[Bad Base64 input character decimal 123 in array position 0]; ', 'ElasticsearchIllegalArgumentException[Failed to decode scrollId]; nested: IOException[Bad Base64 input character decimal 123 in array position 0]; ')

The same code, when used in another elasticsearch (5.5.2), works perfectly.

Googling led me to this page, which suggested the issue existed in ES version <= 1.5.

I'm wondering if is there a way to fix this issue without updating ES, or I either have to update ES or not use Scroll at all?

Thank you in advance!