diff --git a/mod/assign/feedback/editpdf/fpdi/LICENSE b/mod/assign/feedback/editpdf/fpdi/LICENSE
index 7b4f5302921..e33384d2159 100644
--- a/mod/assign/feedback/editpdf/fpdi/LICENSE
+++ b/mod/assign/feedback/editpdf/fpdi/LICENSE
@@ -1,6 +1,6 @@
 The MIT License (MIT)
 
-Copyright (c) 2015 Setasign - Jan Slabon, https://www.setasign.com
+Copyright (c) 2017 Setasign - Jan Slabon, https://www.setasign.com
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
diff --git a/mod/assign/feedback/editpdf/fpdi/filters/FilterASCII85.php b/mod/assign/feedback/editpdf/fpdi/filters/FilterASCII85.php
index b7e89663292..dc100c4c70f 100644
--- a/mod/assign/feedback/editpdf/fpdi/filters/FilterASCII85.php
+++ b/mod/assign/feedback/editpdf/fpdi/filters/FilterASCII85.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 /**
diff --git a/mod/assign/feedback/editpdf/fpdi/filters/FilterASCIIHexDecode.php b/mod/assign/feedback/editpdf/fpdi/filters/FilterASCIIHexDecode.php
index 66ddae48392..3c29a952b7e 100644
--- a/mod/assign/feedback/editpdf/fpdi/filters/FilterASCIIHexDecode.php
+++ b/mod/assign/feedback/editpdf/fpdi/filters/FilterASCIIHexDecode.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 /**
diff --git a/mod/assign/feedback/editpdf/fpdi/filters/FilterLZW.php b/mod/assign/feedback/editpdf/fpdi/filters/FilterLZW.php
index f855d22c7aa..c3d26ad5d79 100644
--- a/mod/assign/feedback/editpdf/fpdi/filters/FilterLZW.php
+++ b/mod/assign/feedback/editpdf/fpdi/filters/FilterLZW.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 /**
diff --git a/mod/assign/feedback/editpdf/fpdi/fpdf_tpl.php b/mod/assign/feedback/editpdf/fpdi/fpdf_tpl.php
index de746dda313..47592b270a3 100644
--- a/mod/assign/feedback/editpdf/fpdi/fpdf_tpl.php
+++ b/mod/assign/feedback/editpdf/fpdi/fpdf_tpl.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 if (!class_exists('fpdi_bridge')) {
diff --git a/mod/assign/feedback/editpdf/fpdi/fpdi.php b/mod/assign/feedback/editpdf/fpdi/fpdi.php
index 8ecc661d8e4..926deb5397b 100644
--- a/mod/assign/feedback/editpdf/fpdi/fpdi.php
+++ b/mod/assign/feedback/editpdf/fpdi/fpdi.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 if (!class_exists('FPDF_TPL')) {
@@ -22,7 +22,7 @@ class FPDI extends FPDF_TPL
      *
      * @string
      */
-    const VERSION = '1.6.1';
+    const VERSION = '1.6.2';
 
     /**
      * Actual filename
@@ -88,6 +88,7 @@ class FPDI extends FPDF_TPL
      *
      * @param string $filename A valid path to the PDF document from which pages should be imported from
      * @return int The number of pages in the document
+     * @throws Exception
      */
     public function setSourceFile($filename)
     {
@@ -95,16 +96,27 @@ class FPDI extends FPDF_TPL
         if (false !== $_filename)
             $filename = $_filename;
 
-        $this->currentFilename = $filename;
-        
-        if (!isset($this->parsers[$filename])) {
-            $this->parsers[$filename] = $this->_getPdfParser($filename);
-            $this->setPdfVersion(
-                max($this->getPdfVersion(), $this->parsers[$filename]->getPdfVersion())
-            );
-        }
+        $currentFilename = $this->currentFilename;
+        $currentParser = $this->currentParser;
 
-        $this->currentParser = $this->parsers[$filename];
+        try {
+            $this->currentFilename = $filename;
+
+            if (!isset($this->parsers[$filename])) {
+                $this->parsers[$filename] = $this->_getPdfParser($filename);
+                $this->setPdfVersion(
+                    max($this->getPdfVersion(), $this->parsers[$filename]->getPdfVersion())
+                );
+            }
+
+            $this->currentParser = $this->parsers[$filename];
+
+        } catch (Exception $e) {
+            unset($this->parsers[$filename]);
+            $this->currentFilename = $currentFilename;
+            $this->currentParser = $currentParser;
+            throw $e;
+        }
         
         return $this->parsers[$filename]->getPageCount();
     }
diff --git a/mod/assign/feedback/editpdf/fpdi/fpdi_bridge.php b/mod/assign/feedback/editpdf/fpdi/fpdi_bridge.php
index 2062185378f..8283876b171 100644
--- a/mod/assign/feedback/editpdf/fpdi/fpdi_bridge.php
+++ b/mod/assign/feedback/editpdf/fpdi/fpdi_bridge.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 /**
@@ -16,12 +16,21 @@
  * This way it is possible to use FPDI for both FPDF and TCPDF with one FPDI version.
  */
 
+if (!class_exists('TCPDF', false)) {
     /**
      * Class fpdi_bridge
-     *
-     * This has been modified to use the Moodle pdf class which in turn extends the TCPDF class.
      */
-    class fpdi_bridge extends pdf
+    class fpdi_bridge extends FPDF
+    {
+        // empty body
+    }
+
+} else {
+
+    /**
+     * Class fpdi_bridge
+     */
+    class fpdi_bridge extends TCPDF
     {
         /**
          * Array of Tpl-Data
@@ -194,3 +203,4 @@
             return current(unpack('H*', $str));
         }
     }
+}
\ No newline at end of file
diff --git a/mod/assign/feedback/editpdf/fpdi/fpdi_pdf_parser.php b/mod/assign/feedback/editpdf/fpdi/fpdi_pdf_parser.php
index 9e6d521a4cb..0204b9c919f 100644
--- a/mod/assign/feedback/editpdf/fpdi/fpdi_pdf_parser.php
+++ b/mod/assign/feedback/editpdf/fpdi/fpdi_pdf_parser.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (http://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 if (!class_exists('pdf_parser')) {
@@ -155,6 +155,10 @@ class fpdi_pdf_parser extends pdf_parser
         if (isset($this->_pages[$this->pageNo][1][1]['/Contents'])) {
             $contents = $this->_getPageContent($this->_pages[$this->pageNo][1][1]['/Contents']);
             foreach ($contents AS $tmpContent) {
+                if ($tmpContent[0] !== pdf_parser::TYPE_STREAM) {
+                    continue;
+                }
+
                 $buffer .= $this->_unFilterStream($tmpContent) . ' ';
             }
         }
@@ -335,6 +339,10 @@ class fpdi_pdf_parser extends pdf_parser
 
         foreach ($kids as $v) {
             $pg = $this->resolveObject($v);
+            if ($pg[0] !== pdf_parser::TYPE_OBJECT) {
+                throw new Exception('Invalid data type in page tree.');
+            }
+
             if ($pg[1][1]['/Type'][1] === '/Pages') {
                 // If one of the kids is an embedded
                 // /Pages array, resolve it as well.
diff --git a/mod/assign/feedback/editpdf/fpdi/pdf_context.php b/mod/assign/feedback/editpdf/fpdi/pdf_context.php
index 474aa72e4a8..dac38b49a27 100644
--- a/mod/assign/feedback/editpdf/fpdi/pdf_context.php
+++ b/mod/assign/feedback/editpdf/fpdi/pdf_context.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 /**
@@ -67,7 +67,14 @@ class pdf_context
     public function getPos()
     {
         if ($this->_mode == 0) {
-            return ftell($this->file);
+            if (feof($this->file)) {
+                $stat = fstat($this->file);
+                fseek($this->file, $stat['size']);
+            }
+
+            $pos = ftell($this->file);
+
+            return $pos;
         } else {
             return 0;
         }
@@ -85,7 +92,7 @@ class pdf_context
     {
         if ($this->_mode == 0) {
             if (!is_null($pos)) {
-                fseek ($this->file, $pos);
+                fseek($this->file, $pos);
             }
 
             $this->buffer = $l > 0 ? fread($this->file, $l) : '';
diff --git a/mod/assign/feedback/editpdf/fpdi/pdf_parser.php b/mod/assign/feedback/editpdf/fpdi/pdf_parser.php
index 490b1350c79..6151cb5cf03 100644
--- a/mod/assign/feedback/editpdf/fpdi/pdf_parser.php
+++ b/mod/assign/feedback/editpdf/fpdi/pdf_parser.php
@@ -3,9 +3,9 @@
  * This file is part of FPDI
  *
  * @package   FPDI
- * @copyright Copyright (c) 2015 Setasign - Jan Slabon (http://www.setasign.com)
+ * @copyright Copyright (c) 2017 Setasign - Jan Slabon (https://www.setasign.com)
  * @license   http://opensource.org/licenses/mit-license The MIT License
- * @version   1.6.1
+ * @version   1.6.2
  */
 
 /**
diff --git a/mod/assign/feedback/editpdf/fpdi/readme_moodle.txt b/mod/assign/feedback/editpdf/fpdi/readme_moodle.txt
index edc01d85d79..467cf935660 100644
--- a/mod/assign/feedback/editpdf/fpdi/readme_moodle.txt
+++ b/mod/assign/feedback/editpdf/fpdi/readme_moodle.txt
@@ -19,6 +19,14 @@ Installation
 3) Update mod/assign/feedback/editpdf/fpdi/fpdi_bridge.php (or the replacement file) to extend 'pdf' instead of 'TCPDF'.
 4) Make a note below of any changes made.
 
+2017/10/03
+----------
+1/ Updated to 1.6.2
+2/ Cherry-picked changes in MDL-55848
+3/ Renamed 'TCPDF' to 'pdf' as stated above.
+
+Updated by Ankit Agarwal<ankit.agrr@gmail.com> (MDL-60301)
+
 2016/11/15
 ----------
 
diff --git a/mod/assign/feedback/editpdf/thirdpartylibs.xml b/mod/assign/feedback/editpdf/thirdpartylibs.xml
index cf10e9b1496..7a80291e4dc 100644
--- a/mod/assign/feedback/editpdf/thirdpartylibs.xml
+++ b/mod/assign/feedback/editpdf/thirdpartylibs.xml
@@ -4,7 +4,7 @@
     <location>fpdi</location>
     <name>FPDI</name>
     <license>MIT</license>
-    <version>1.6.1</version>
+    <version>1.6.2</version>
     <licenseversion></licenseversion>
   </library>
 </libraries>