diff --git a/application/Espo/Core/Pdf/Tcpdf.php b/application/Espo/Core/Pdf/Tcpdf.php
index 03da6ab085..b9f16d053e 100644
--- a/application/Espo/Core/Pdf/Tcpdf.php
+++ b/application/Espo/Core/Pdf/Tcpdf.php
@@ -27,11 +27,6 @@
  * these Appropriate Legal Notices must retain the display of the "EspoCRM" word.
  ************************************************************************/
 
-/************************************************************************
- * This file contains code parts copied from TCPDF software library
- * that is published under GNU Lesser General Public License.
- ************************************************************************/
-
 namespace Espo\Core\Pdf;
 
 define('K_TCPDF_EXTERNAL_CONFIG', true);
@@ -69,6 +64,8 @@ require "vendor/tecnickcom/tcpdf/tcpdf.php";
 use \TCPDF_STATIC;
 use \TCPDF_FONTS;
 
+use Espo\Core\Utils\Util;
+
 class Tcpdf extends \TCPDF
 {
     protected $footerHtml = '';
@@ -169,167 +166,6 @@ class Tcpdf extends \TCPDF
         $this->SetAutoPageBreak($autoPageBreak, $breakMargin);
     }
 
-    protected function _putpages()
-    {
-        $filter = ($this->compress) ? '/Filter /FlateDecode ' : '';
-        // get internal aliases for page numbers
-        $pnalias = $this->getAllInternalPageNumberAliases();
-        $num_pages = $this->numpages;
-        $ptpa = TCPDF_STATIC::formatPageNumber(($this->starting_page_number + $num_pages - 1));
-        $ptpu = TCPDF_FONTS::UTF8ToUTF16BE($ptpa, false, $this->isunicode, $this->CurrentFont);
-        $ptp_num_chars = $this->GetNumChars($ptpa);
-        $pagegroupnum = 0;
-        $groupnum = 0;
-        $ptgu = 1;
-        $ptga = 1;
-        $ptg_num_chars = 1;
-        for ($n = 1; $n <= $num_pages; ++$n) {
-            // get current page
-            $temppage = $this->getPageBuffer($n);
-            $pagelen = strlen($temppage);
-            // set replacements for total pages number
-            $pnpa = TCPDF_STATIC::formatPageNumber(($this->starting_page_number + $n - 1));
-            $pnpu = TCPDF_FONTS::UTF8ToUTF16BE($pnpa, false, $this->isunicode, $this->CurrentFont);
-            $pnp_num_chars = $this->GetNumChars($pnpa);
-            $pdiff = 0; // difference used for right shift alignment of page numbers
-            $gdiff = 0; // difference used for right shift alignment of page group numbers
-            if (!empty($this->pagegroups)) {
-                if (isset($this->newpagegroup[$n])) {
-                    $pagegroupnum = 0;
-                    ++$groupnum;
-                    $ptga = TCPDF_STATIC::formatPageNumber($this->pagegroups[$groupnum]);
-                    $ptgu = TCPDF_FONTS::UTF8ToUTF16BE($ptga, false, $this->isunicode, $this->CurrentFont);
-                    $ptg_num_chars = $this->GetNumChars($ptga);
-                }
-                ++$pagegroupnum;
-                $pnga = TCPDF_STATIC::formatPageNumber($pagegroupnum);
-                $pngu = TCPDF_FONTS::UTF8ToUTF16BE($pnga, false, $this->isunicode, $this->CurrentFont);
-
-                $pnga = $pngu;
-
-                $png_num_chars = $this->GetNumChars($pnga);
-                // replace page numbers
-                $replace = array();
-                $replace[] = array($ptgu, $ptg_num_chars, 9, $pnalias[2]['u']);
-                $replace[] = array($ptga, $ptg_num_chars, 7, $pnalias[2]['a']);
-                $replace[] = array($pngu, $png_num_chars, 9, $pnalias[3]['u']);
-                $replace[] = array($pnga, $png_num_chars, 7, $pnalias[3]['a']);
-                list($temppage, $gdiff) = TCPDF_STATIC::replacePageNumAliases($temppage, $replace, $gdiff);
-            }
-            // replace page numbers
-            $replace = array();
-            $replace[] = array($ptpu, $ptp_num_chars, 9, $pnalias[0]['u']);
-            $replace[] = array($ptpa, $ptp_num_chars, 7, $pnalias[0]['a']);
-            $replace[] = array($pnpu, $pnp_num_chars, 9, $pnalias[1]['u']);
-
-            $pnpa = $pnpu;
-
-            $replace[] = array($pnpa, $pnp_num_chars, 7, $pnalias[1]['a']);
-            list($temppage, $pdiff) = TCPDF_STATIC::replacePageNumAliases($temppage, $replace, $pdiff);
-            // replace right shift alias
-            $temppage = $this->replaceRightShiftPageNumAliases($temppage, $pnalias[4], max($pdiff, $gdiff));
-            // replace EPS marker
-            $temppage = str_replace($this->epsmarker, '', $temppage);
-            //Page
-            $this->page_obj_id[$n] = $this->_newobj();
-            $out = '<<';
-            $out .= ' /Type /Page';
-            $out .= ' /Parent 1 0 R';
-            if (empty($this->signature_data['approval']) OR ($this->signature_data['approval'] != 'A')) {
-                $out .= ' /LastModified '.$this->_datestring(0, $this->doc_modification_timestamp);
-            }
-            $out .= ' /Resources 2 0 R';
-            foreach ($this->page_boxes as $box) {
-                $out .= ' /'.$box;
-                $out .= sprintf(' [%F %F %F %F]', $this->pagedim[$n][$box]['llx'], $this->pagedim[$n][$box]['lly'], $this->pagedim[$n][$box]['urx'], $this->pagedim[$n][$box]['ury']);
-            }
-            if (isset($this->pagedim[$n]['BoxColorInfo']) AND !empty($this->pagedim[$n]['BoxColorInfo'])) {
-                $out .= ' /BoxColorInfo <<';
-                foreach ($this->page_boxes as $box) {
-                    if (isset($this->pagedim[$n]['BoxColorInfo'][$box])) {
-                        $out .= ' /'.$box.' <<';
-                        if (isset($this->pagedim[$n]['BoxColorInfo'][$box]['C'])) {
-                            $color = $this->pagedim[$n]['BoxColorInfo'][$box]['C'];
-                            $out .= ' /C [';
-                            $out .= sprintf(' %F %F %F', ($color[0] / 255), ($color[1] / 255), ($color[2] / 255));
-                            $out .= ' ]';
-                        }
-                        if (isset($this->pagedim[$n]['BoxColorInfo'][$box]['W'])) {
-                            $out .= ' /W '.($this->pagedim[$n]['BoxColorInfo'][$box]['W'] * $this->k);
-                        }
-                        if (isset($this->pagedim[$n]['BoxColorInfo'][$box]['S'])) {
-                            $out .= ' /S /'.$this->pagedim[$n]['BoxColorInfo'][$box]['S'];
-                        }
-                        if (isset($this->pagedim[$n]['BoxColorInfo'][$box]['D'])) {
-                            $dashes = $this->pagedim[$n]['BoxColorInfo'][$box]['D'];
-                            $out .= ' /D [';
-                            foreach ($dashes as $dash) {
-                                $out .= sprintf(' %F', ($dash * $this->k));
-                            }
-                            $out .= ' ]';
-                        }
-                        $out .= ' >>';
-                    }
-                }
-                $out .= ' >>';
-            }
-            $out .= ' /Contents '.($this->n + 1).' 0 R';
-            $out .= ' /Rotate '.$this->pagedim[$n]['Rotate'];
-            if (!$this->pdfa_mode) {
-                $out .= ' /Group << /Type /Group /S /Transparency /CS /DeviceRGB >>';
-            }
-            if (isset($this->pagedim[$n]['trans']) AND !empty($this->pagedim[$n]['trans'])) {
-                // page transitions
-                if (isset($this->pagedim[$n]['trans']['Dur'])) {
-                    $out .= ' /Dur '.$this->pagedim[$n]['trans']['Dur'];
-                }
-                $out .= ' /Trans <<';
-                $out .= ' /Type /Trans';
-                if (isset($this->pagedim[$n]['trans']['S'])) {
-                    $out .= ' /S /'.$this->pagedim[$n]['trans']['S'];
-                }
-                if (isset($this->pagedim[$n]['trans']['D'])) {
-                    $out .= ' /D '.$this->pagedim[$n]['trans']['D'];
-                }
-                if (isset($this->pagedim[$n]['trans']['Dm'])) {
-                    $out .= ' /Dm /'.$this->pagedim[$n]['trans']['Dm'];
-                }
-                if (isset($this->pagedim[$n]['trans']['M'])) {
-                    $out .= ' /M /'.$this->pagedim[$n]['trans']['M'];
-                }
-                if (isset($this->pagedim[$n]['trans']['Di'])) {
-                    $out .= ' /Di '.$this->pagedim[$n]['trans']['Di'];
-                }
-                if (isset($this->pagedim[$n]['trans']['SS'])) {
-                    $out .= ' /SS '.$this->pagedim[$n]['trans']['SS'];
-                }
-                if (isset($this->pagedim[$n]['trans']['B'])) {
-                    $out .= ' /B '.$this->pagedim[$n]['trans']['B'];
-                }
-                $out .= ' >>';
-            }
-            $out .= $this->_getannotsrefs($n);
-            $out .= ' /PZ '.$this->pagedim[$n]['PZ'];
-            $out .= ' >>';
-            $out .= "\n".'endobj';
-            $this->_out($out);
-            //Page content
-            $p = ($this->compress) ? gzcompress($temppage) : $temppage;
-            $this->_newobj();
-            $p = $this->_getrawstream($p);
-            $this->_out('<<'.$filter.'/Length '.strlen($p).'>> stream'."\n".$p."\n".'endstream'."\n".'endobj');
-        }
-        //Pages root
-        $out = $this->_getobj(1)."\n";
-        $out .= '<< /Type /Pages /Kids [';
-        foreach($this->page_obj_id as $page_obj) {
-            $out .= ' '.$page_obj.' 0 R';
-        }
-        $out .= ' ] /Count '.$num_pages.' >>';
-        $out .= "\n".'endobj';
-        $this->_out($out);
-    }
-
     public function Output($name = 'doc.pdf', $dest = 'I')
     {
         if ($dest === 'I' && !$this->sign && php_sapi_name() != 'cli') {
@@ -337,7 +173,7 @@ class Tcpdf extends \TCPDF
                 $this->Close();
             }
             $name = preg_replace('/[\s]+/', '_', $name);
-            $name = \Espo\Core\Utils\Util::sanitizeFileName($name);
+            $name = Util::sanitizeFileName($name);
 
             if (ob_get_contents()) {
                 $this->Error('Some data has already been output, can\'t send PDF file');
diff --git a/composer.json b/composer.json
index 87cb13ece5..50e49c2054 100644
--- a/composer.json
+++ b/composer.json
@@ -28,7 +28,7 @@
         "yzalis/identicon": "*",
         "zordius/lightncandy": "1.*",
         "composer/semver": "^1.4",
-        "tecnickcom/tcpdf": "^6.2",
+        "tecnickcom/tcpdf": "^6.3",
         "zbateson/mail-mime-parser": "1.2.*",
         "phpoffice/phpspreadsheet": "^1.10",
         "spatie/async": "dev-for-espocrm",
diff --git a/composer.lock b/composer.lock
index 38cb334b10..d5ccf2c7f8 100644
--- a/composer.lock
+++ b/composer.lock
@@ -4,7 +4,7 @@
         "Read more about it at https://getcomposer.org/doc/01-basic-usage.md#installing-dependencies",
         "This file is @generated automatically"
     ],
-    "content-hash": "c581826c89ac8f6b8d1c708cf83f77f1",
+    "content-hash": "7df8ab50657d690174bf26a67aa0afdf",
     "packages": [
         {
             "name": "cboden/ratchet",
@@ -3582,16 +3582,16 @@
         },
         {
             "name": "tecnickcom/tcpdf",
-            "version": "6.2.17",
+            "version": "6.3.5",
             "source": {
                 "type": "git",
                 "url": "https://github.com/tecnickcom/TCPDF.git",
-                "reference": "64fc19439863e1b1314487a72a74d9bfd0b55a53"
+                "reference": "19a535eaa7fb1c1cac499109deeb1a7a201b4549"
             },
             "dist": {
                 "type": "zip",
-                "url": "https://api.github.com/repos/tecnickcom/TCPDF/zipball/64fc19439863e1b1314487a72a74d9bfd0b55a53",
-                "reference": "64fc19439863e1b1314487a72a74d9bfd0b55a53",
+                "url": "https://api.github.com/repos/tecnickcom/TCPDF/zipball/19a535eaa7fb1c1cac499109deeb1a7a201b4549",
+                "reference": "19a535eaa7fb1c1cac499109deeb1a7a201b4549",
                 "shasum": ""
             },
             "require": {
@@ -3620,7 +3620,7 @@
             },
             "notification-url": "https://packagist.org/downloads/",
             "license": [
-                "LGPL-3.0"
+                "LGPL-3.0-only"
             ],
             "authors": [
                 {
@@ -3640,7 +3640,7 @@
                 "pdf417",
                 "qrcode"
             ],
-            "time": "2018-02-24T11:48:20+00:00"
+            "time": "2020-02-14T14:20:12+00:00"
         },
         {
             "name": "true/punycode",