Slim Application Error

The application could not run because of the following error:

Details

Type: ErrorException

Code: 2

Message: Cannot modify header information - headers already sent by (output started at /home/vadiyaka/public_html/index.php:1)

File: /home/vadiyaka/public_html/src/functions.php

Line: 64

Trace

#0 [internal function]: Slim\Slim::handleErrors(2, 'Cannot modify h...', '/home/vadiyaka/...', 64, Array)
#1 /home/vadiyaka/public_html/src/functions.php(64): setcookie('guest', 'c496a214c7b64cf...', 1742631927, '/', 'vadiyaka.com')
#2 /home/vadiyaka/public_html/src/functions.php(21): addGuest()
#3 /home/vadiyaka/public_html/src/routes.php(5): guestLogActivity('index')
#4 [internal function]: {closure}()
#5 /home/vadiyaka/public_html/Slim/Route.php(468): call_user_func_array(Object(Closure), Array)
#6 /home/vadiyaka/public_html/Slim/Slim.php(1357): Slim\Route->dispatch()
#7 /home/vadiyaka/public_html/Slim/Middleware/Flash.php(85): Slim\Slim->call()
#8 /home/vadiyaka/public_html/Slim/Middleware/MethodOverride.php(92): Slim\Middleware\Flash->call()
#9 /home/vadiyaka/public_html/Slim/Middleware/PrettyExceptions.php(67): Slim\Middleware\MethodOverride->call()
#10 /home/vadiyaka/public_html/Slim/Slim.php(1302): Slim\Middleware\PrettyExceptions->call()
#11 /home/vadiyaka/public_html/index.php(58): Slim\Slim->run()
#12 {main}