O que esta rolando nesta session

Warning: session_start(): open(/tmp\sess_8ffe940aa8676a4499e553da9187d1e6, O_RDWR) failed: No such file or directory (2) in C:\Arquivos de programas\Apache Group\Apache2\htdocs\cadastro\cadastro\index.php on line 38Warning: session_start(): Cannot send session cookie - headers already sent by (output started at C:\Arquivos de programas\Apache Group\Apache2\htdocs\cadastro\cadastro\index.php:38) in C:\Arquivos de programas\Apache Group\Apache2\htdocs\cadastro\cadastro\index.php on line 38Warning: session_start(): Cannot send session cache limiter - headers already sent (output started at C:\Arquivos de programas\Apache Group\Apache2\htdocs\cadastro\cadastro\index.php:38) in C:\Arquivos de programas\Apache Group\Apache2\htdocs\cadastro\cadastro\index.php on line 38Warning: Cannot modify header information - headers already sent by (output started at C:\Arquivos de programas\Apache Group\Apache2\htdocs\cadastro\cadastro\index.php:38) in C:\Arquivos de programas\Apache Group\Apache2\htdocs\cadastro\cadastro\index.php on line 44Warning: Unknown(): Your script possibly relies on a session side-effect which existed until PHP 4.2.3. Please be advised that the session extension does not consider global variables as a source of data, unless register_globals is enabled. You can disable this functionality and this warning by setting session.bug_compat_42 or session.bug_compat_warn to off, respectively. in Unknown on line 0Warning: Unknown(): open(/tmp\sess_8ffe940aa8676a4499e553da9187d1e6, O_RDWR) failed: No such file or directory (2) in Unknown on line 0Warning: Unknown(): Failed to write session data (files). Please verify that the current setting of session.save_path is correct (/tmp) in Unknown on line 0