Compile Error: Cannot use empty array elements in arrays (500 Whoops, looks like something went wrong.)

Compile Error: Cannot use empty array elements in arrays

Exception

Symfony\Component\ErrorHandler\Error\ FatalError

  1.     if ($debug) { echo "$DEBUG__LINE__ ": function: " __FUNCTION__ "</b> BEFORE MAIL</b> script_mail = $script_mail"; }
  2.     $msg_header "From: USBF Trigger <al@usbf.org>";
  3.     $task_team = array("default","investigate","delete","deleteOK","entryform","makechange","changeteam","doentry","list");
  4.     $task_ssf = array("default",,"edit","getacblno","display","ssf","copyssf","makecopy","formssf","deletessf","OKdeletessf"
  5.                         ,"asfdisplay","formasf","deleteasf","OKdeleteasf");
  6.     if (!in_array($task,$task_team) && !in_array($task,$task_ssf))
  7.     {
  8.         // ?? just set flag then rest handled inside normal remaining email setup

Stack Trace

FatalError
Symfony\Component\ErrorHandler\Error\FatalError:
Compile Error: Cannot use empty array elements in arrays

  at /home/usbf/public_html/apps/includes/Functions_common.php:138