Scheduler expects xml file to be sent to him during loading and he is expecting to receive one after update operation. The problem is that while he receives such file it isn’t treated as xml but as simple text.
What you can do:
Check your php files — one of them must have whitespace (empty line, space and so on) at the beginning or end of it, you need to remove whitespaces.
Or you can try and remove <?xml version='1.0' encoding='utf-8'?> line from the scheduler source code. While such xml will be incorrect it will still be treated like xml.
Best regards,
Ilya
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