Index: typo3_src/t3lib/class.t3lib_befunc.php
===================================================================
--- typo3_src/t3lib/class.t3lib_befunc.php	(revision 6087)
+++ typo3_src/t3lib/class.t3lib_befunc.php	(working copy)
@@ -1779,6 +1779,17 @@
 					$theFile_abs = PATH_site.($uploaddir?$uploaddir.'/':'').trim($theFile);
 					$theFile = ($abs?'':'../').($uploaddir?$uploaddir.'/':'').trim($theFile);
 
+					if (!file_exists($theFile_abs)) {
+						$flashMessage = t3lib_div::makeInstance(
+							't3lib_FlashMessage',
+							$GLOBALS['LANG']->sL('LLL:EXT:lang/locallang_core.xml:warning.file_missing_text') . ' <abbr title="' . $theFile_abs . '">' . $theFile . '</abbr>',
+							$GLOBALS['LANG']->sL('LLL:EXT:lang/locallang_core.xml:warning.file_missing'),
+							t3lib_FlashMessage::ERROR
+						);
+						$thumbData .= $flashMessage->render();
+						continue;
+					}
+
 					$check = basename($theFile_abs).':'.filemtime($theFile_abs).':'.$GLOBALS['TYPO3_CONF_VARS']['SYS']['encryptionKey'];
 					$params = '&file='.rawurlencode($theFile);
 					$params.= $size?'&size='.$size:'';
Index: typo3_src/typo3/sysext/lang/locallang_core.xml
===================================================================
--- typo3_src/typo3/sysext/lang/locallang_core.xml	(revision 6087)
+++ typo3_src/typo3/sysext/lang/locallang_core.xml	(working copy)
@@ -251,6 +251,8 @@
 			<label index="warning.header">Important Notice!</label>
 			<label index="warning.backend_reference">The Reference Index table is empty which is likely the result of a recent TYPO3 upgrade. Please go to %sTools&gt;DB Check%s and update the reference index.</label>
 			<label index="warning.memcache_not_usable">Memcache is configured, but connection to memcached failed with these configuration(s):</label>
+			<label index="warning.file_missing">File is missing!</label>
+			<label index="warning.file_missing_text">This content element references a file which seems to not exist:</label>
 			<label index="toolbarItems.shortcuts">Shortcuts</label>
 			<label index="toolbarItems.shortcut">Shortcut</label>
 			<label index="toolbarItems.shortcutsGroup">Shortcut Group</label>