raster data from netcdf is rendered black

console shows the following error:

...
error in gradient LinearGradient {start: 0, end: 255, colorStop: Array(5), color: {…}, addColorStop: ƒ, …} 1323.75 Gradient.ts:181
error in gradient LinearGradient {start: 0, end: 255, colorStop: Array(5), color: {…}, addColorStop: ƒ, …} 1318.6666666666667 Gradient.ts:181
error in gradient LinearGradient {start: 0, end: 255, colorStop: Array(5), color: {…}, addColorStop: ƒ, …} 1328.5 Gradient.ts:181
...