[SOLVED] CI 3.1.0 ImageMagick not working

Platform: Ubuntu 16.0.4.1
CI Ver:  3.1.0

Can someone please check the following:

file: system/libraries/Image_lib.php

PHP Code:

// __LINE__ 890
// exec() might be disabled
if (function_usable('exec'))
{
  #@exec($cmd, $output, $retval);
  if(0):
    # ORIGINAL SCRIPT NOT WORKING 
    @exec($cmd, $output, $retval);
  else:
    # THIS WORKS OK
    @exec('/usr/bin/convert ' 
          .$this->full_src_path 
          .' -thumbnail ' .$this->width.'x'.$this->height .' '
          .$this->full_dst_path 
          .' 2>&1', $retval);       
        $retval = count($retval);
  endif;      
}#endif (function_usable('exec')) 


I was also unable to get ImageMagick working in previous versions and had to use PHP exec('convert'... );