Hi João,
the error reported by JOSM validator is as follows:
"Role for multipolygon member should be inner or outer"

OSMI shows the same error: "Role should be outer"

These errors obviously refer to your labeling of the relation items "member".

I have reverted this changeset now, so you can fix it yourself. OSMI take an other night to show this error, but if you use JOSM you can check for the error right now.
Kind regards
Guido