session_start(): Cannot send session cache limiter – headers already sent

Error Message: session_start(): Cannot send session cache limiter - headers already sent. There can be many possibilities when it will show above mentioned error.

Some of the reasons are :

• Some white space before <?php  php start tag of after ?> php close tag
• Session is not started in the top of the code
• There may be some space before starting on session
• There may be some echo before session
• There may be some notifications or warnings printed

Some Tricks

• Remove white spaces from the top of the file or included file
• Remove white space before session_start()
  
• Write session_start() at the top of the file
• Display warning notification of:

error_reporting(e_all);

ini_set('display_errors', 0);

• There should not be an echo used before header redirect

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