Twitter Bootstrap 3 icon displaying a square

Try re-downloading the fonts, may be corrupt.

Check the MD5

MD5 (glyphicons-halflings-regular.eot) = 2469ccfe446daa49d5c1446732d1436d
MD5 (glyphicons-halflings-regular.svg) = 3b31e1de93290779334c84c9b07c6eed
MD5 (glyphicons-halflings-regular.ttf) = aa9c7490c2fd52cb96c729753cc4f2d5
MD5 (glyphicons-halflings-regular.woff) = 7c4cbe928205c888831ba76548563ca3