Me pide valoración antes de siquiera poder usarla

When I try to download files from Opera GX, it tells me they weigh 0 bits or sometimes it doesn't even let me download them. This happens to me on my university's website and on format conversion pages (such as Convertio, I Love PDF, etc.).
Does anyone know how to fix this?

My download on My university page (powered bye Phoenix)

And My try from convertio