How to fix an error in the third line of the Yandex YML file (price list)?

Question

Yandex

Good afternoon!
I can't beat the problem for a long time. There is a generator of price lists in YML format. The first four lines are the following:
<?xml version="1.0" encoding="windows-1251"?>
When validating with a checker on the site https://webmaster.yandex.com/xsdtest.xml , the following error constantly occurs:
unknown XSD element
Line: 3 Column: 38
More
cvc-elt.1.a: Cannot find the declaration of element 'yml_catalog'.
On the Internet, I see that many people have such an error - but I have not found an answer on how to treat it. Previously, the generated file was checked by the checker normally. The error occurred recently. I can't say exactly when, but I suspect it may have happened after the site was moved from http:// to https://. But, a few price lists I've found don't pass validation with exactly this- same mistake!
What can be wrong?

Answer 1

Actually, the problem is joxi.ru/krD9Y5Vfd5q8mp.... if you select the wrong section, we get an error, since the xml structure is slightly different