The VoxelHeightExecutor and VoxelCenterExecutor catch ArrayIndexOutOfBoundsException's but refer to the array in the next line:
https://github.com/IntellectualSites/FastAsyncVoxelSniper/blob/c18e69605c146588492a8f8493139ebf7252e9ae/src/main/java/com/thevoxelbox/voxelsniper/command/executor/VoxelCenterExecutor.java#L39-L44
If no input is provided, an AIOOBE is thrown again, because the array we're referring to is empty.