TYPO3 Core

Setting up a clean TYPO3 7.4 installation on a MAMP 3.4 environment with php 5.6.10 (no caches like opcode, APCu etc) leads to a failure in rendering the tree section: no icon to generate page entries are shown, neither are page shown that have been copied over from another TYPO3 instance via SQL.

The log file contains these error messages:

Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /[PATH]/typo3_src-7.4.0/typo3/sysext/core/Classes/Core/Bootstrap.php line 1113    

Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /[PATH]/typo3_src-7.4.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 423    

Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /[PATH]/typo3_src-7.4.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 422    

Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /[PATH]/typo3_src-7.4.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 409    

Core: Error handler (BE): PHP Warning: Cannot modify header information - headers already sent in /[PATH]/typo3_src-7.4.0/typo3/sysext/core/Classes/Authentication/AbstractUserAuthentication.php line 408

which reference these 2 functions:

- Bootstrap.php

/**
 * Send HTTP headers if configured
 *
 * @return Bootstrap
 * @internal This is not a public API method, do not use in own extensions
 */
public function sendHttpHeaders() {
    if (!empty($GLOBALS['TYPO3_CONF_VARS']['BE']['HTTP']['Response']['Headers']) && is_array($GLOBALS['TYPO3_CONF_VARS']['BE']['HTTP']['Response']['Headers'])) {
        foreach ($GLOBALS['TYPO3_CONF_VARS']['BE']['HTTP']['Response']['Headers'] as $header) {
            header($header);
        }
    }
    return $this;
}

- AbstractUserAuthentication

if ($this->sendNoCacheHeaders && !(TYPO3_REQUESTTYPE & TYPO3_REQUESTTYPE_CLI)) {
    header('Expires: 0');
    header('Last-Modified: ' . gmdate('D, d M Y H:i:s') . ' GMT');
    $cacheControlHeader = 'no-cache, must-revalidate';
    $pragmaHeader = 'no-cache';
    // Prevent error message in IE when using a https connection
    // see http://forge.typo3.org/issues/24125
    $clientInfo = GeneralUtility::clientInfo();
    if ($clientInfo['BROWSER'] === 'msie' && GeneralUtility::getIndpEnv('TYPO3_SSL')) {
        // Some IEs can not handle no-cache
        // see http://support.microsoft.com/kb/323308/en-us
        $cacheControlHeader = 'must-revalidate';
        // IE needs "Pragma: private" if SSL connection
        $pragmaHeader = 'private';
    }
    header('Cache-Control: ' . $cacheControlHeader);
    header('Pragma: ' . $pragmaHeader);
}

When switching back to php 5.5.26, everything works fine.