Q: I have a MBP (Late 2011). I'm having problems and tried to access Internet Recovery and get the message apple.com/support 501 0F.

last time I got something like this I had to change my network connection in the building to an entirely different host.

you can try

Recommended settings for Wi-Fi routers and access points - Apple Support

or going to another location with a public wi-fi like a coffee shop or the public library or the Apple Store will often allow this, just call apple first with the contact info on the bottom of the page and see if you need to make an appointment first.