Description
For the Pick tool, the input position raster cell values must be within a valid range to determine which input raster will be used to obtain the output raster value. Cell values that are less than 1 or larger than the total number of input raster bands are out of range.
Solution
Check that the position raster is valid and its cell values are within the expected range. If a cell value in the position raster is less than 1, or larger than the total number of rasters in the list, the result will be NoData.