i can't registerFont font ,alweys print ‘Error: Could not parse font file’

I try to use many fonts, but all failed. My code is:

```js
const fs = require("fs");
const Canvas = require('canvas');
const path = require('path')

Canvas.registerFont("./font/Avenir.ttf" ,{ family: "AvenirBook"});
// Canvas.registerFont('./font/BebasNeue.otf',{family:'Bebas Neue'})
// Canvas.registerFont('./font/BebasNeue-Regular.ttf',{family:'Bebas Neue'})
// Canvas.registerFont('./font/koverwatch.ttf',{family:'koverwatch'})
```

canvans version is 2.6.1
node 10.14.1 on windows10

Please help me,thanks.