Google Products plugin xml file

-- HikaShop version -- : 4.4.2
-- PHP version -- : 7.3.28

I have set up plugin to write file to folder on my server. File is generated, but with errors.
This page contains the following errors:
error on line 3566 at column 218: Input is not proper UTF-8, indicate encoding !
Bytes: 0x1F 0x6C 0x6F 0x7A
Below is a rendering of the page up to the first error.

Hi,

Sorry for there is nothing "below" your message. We would need a copy of the file corresponding to that error to be able to check what's going on.
If you have troubles attaching the file to your message, you can use something like this wetransfer.com/

Sorry, but "Below is a rendering of the page up to the first error." was on error page and there was just plain text.
I think I solved a problem.
There was some strange characters in product description. I corected that and now works.