I wanted to export role definitions from one Moodle site to another (from production to beta).

We had made a lot of changes in permissions.

I followed https://docs.moodle.org/2x/pl/Role_export_and_import page and couldn't import XML file.

After debugging in local Docker version I was able to find that XML document cannot be loaded. In the details I found out that line:

<?xml version="1.0" encoding="UTF-8"?> 

should be placed the first line.

I don't know why, but all exported files have 1 empty line at the beginning.