Okay so you weren't asking about Legacy driver with the first clone of this thread. You are asking how to download the driver from AMD Download page.
The link you provided is no good. At least here in the USA.
Here is your R9 270 Download link directly from AMD download page in the USA: https://www.amd.com/en/support/graphics/amd-radeon-r9-series/amd-radeon-r9-200-series/amd-radeon-r9-...
If you get the same result as your link then the problem is with your ISP or AMD Server in your area.