diff --git a/layouts/v7/modules/Documents/CreateDocument.tpl b/layouts/v7/modules/Documents/CreateDocument.tpl
index 8f505629f8477b289472a927add31eed13806012..e6ac00796bed4efd0e2654411aee1b2c2450aa29 100644
--- a/layouts/v7/modules/Documents/CreateDocument.tpl
+++ b/layouts/v7/modules/Documents/CreateDocument.tpl
@@ -28,7 +28,7 @@
 						<input type="hidden" name="relationOperation" value="{$RELATION_OPERATOR}" />
 						<input type="hidden" name="sourceModule" value="{$PARENT_MODULE}" />
 						<input type="hidden" name="sourceRecord" value="{$PARENT_ID}" />
-						{if $RELATION_FIELD_NAME}
+						{if isset($RELATION_FIELD_NAME) && $RELATION_FIELD_NAME}
 							<input type="hidden" name="{$RELATION_FIELD_NAME}" value="{$PARENT_ID}" /> 
 						{/if}
 					{/if}
diff --git a/layouts/v7/modules/Vtiger/uitypes/FileLocationType.tpl b/layouts/v7/modules/Vtiger/uitypes/FileLocationType.tpl
index 2324ed618f6f5b647f68793c22b29ad58cdf64f6..2a478c96669c97ef4566fb5dce15cc41621e78cb 100644
--- a/layouts/v7/modules/Vtiger/uitypes/FileLocationType.tpl
+++ b/layouts/v7/modules/Vtiger/uitypes/FileLocationType.tpl
@@ -12,11 +12,11 @@
 {strip}
 {assign var=FIELD_VALUES value=$FIELD_MODEL->getFileLocationType()}
 {* The options displayed based on the file location type received on request *}
-<select class="select2" name="{$FIELD_MODEL->getFieldName()}" {if $FILE_LOCATION_TYPE eq 'I' OR $FILE_LOCATION_TYPE eq 'E'} disabled {/if}>
+<select class="select2" name="{$FIELD_MODEL->getFieldName()}" {if isset($FILE_LOCATION_TYPE) && ($FILE_LOCATION_TYPE eq 'I' || $FILE_LOCATION_TYPE eq 'E')} disabled {/if}>
 {foreach item=TYPE key=KEY from=$FIELD_VALUES}
-    {if $FILE_LOCATION_TYPE eq 'I'}
+    {if isset($FILE_LOCATION_TYPE) && $FILE_LOCATION_TYPE eq 'I'}
         {assign var=SELECTED value='I'}
-    {elseif $FILE_LOCATION_TYPE eq 'E'}
+    {elseif isset($FILE_LOCATION_TYPE) && $FILE_LOCATION_TYPE eq 'E'}
         {assign var=SELECTED value='E'}
     {else}
         {assign var=SELECTED value=$FIELD_MODEL->get('fieldvalue')}
diff --git a/modules/Documents/Documents.php b/modules/Documents/Documents.php
index 93f0adcb81baeddf9740206440b98b2aa3cc4442..a9a5810edf4ade757fd83283f0555aa4a96b9de7 100644
--- a/modules/Documents/Documents.php
+++ b/modules/Documents/Documents.php
@@ -182,7 +182,7 @@ class Documents extends CRMEntity {
 		{
 			if($files['name'] != '' && $files['size'] > 0 && isset($_REQUEST[$fileindex.'_hidden']))
 			{
-				$files['original_name'] = vtlib_purify($_REQUEST[$fileindex.'_hidden']);
+				$files['original_name'] = isset($_REQUEST[$fileindex.'_hidden']) ? vtlib_purify($_REQUEST[$fileindex.'_hidden']) : "";
 				$file_saved = $this->uploadAndSaveFile($id,$module,$files);
                                 if(!$file_saved){
                                     $log->debug('file upload failed');
@@ -237,9 +237,8 @@ class Documents extends CRMEntity {
 	function getSortOrderForFolder($folderId) {
 		if(isset($_REQUEST['sorder']) && $_REQUEST['folderid'] == $folderId) {
 			$sorder = $this->db->sql_escape_string($_REQUEST['sorder']);
-		} elseif(is_array($_SESSION['NOTES_FOLDER_SORT_ORDER']) &&
-					!empty($_SESSION['NOTES_FOLDER_SORT_ORDER'][$folderId])) {
-				$sorder = $_SESSION['NOTES_FOLDER_SORT_ORDER'][$folderId];
+		} elseif(isset($_SESSION['NOTES_FOLDER_SORT_ORDER']) && is_array($_SESSION['NOTES_FOLDER_SORT_ORDER']) && isset($_SESSION['NOTES_FOLDER_SORT_ORDER'][$folderId]) && !empty($_SESSION['NOTES_FOLDER_SORT_ORDER'][$folderId])) {
+			$sorder = $_SESSION['NOTES_FOLDER_SORT_ORDER'][$folderId];
 		} else {
 			$sorder = $this->default_sort_order;
 		}
@@ -257,8 +256,7 @@ class Documents extends CRMEntity {
 		}
 		if (isset($_REQUEST['order_by'])  && $_REQUEST['folderid'] == $folderId) {
 			$order_by = $this->db->sql_escape_string($_REQUEST['order_by']);
-		} elseif(is_array($_SESSION['NOTES_FOLDER_ORDER_BY']) &&
-				!empty($_SESSION['NOTES_FOLDER_ORDER_BY'][$folderId])) {
+		} elseif(isset($_SESSION['NOTES_FOLDER_ORDER_BY']) && is_array($_SESSION['NOTES_FOLDER_ORDER_BY']) && isset($_SESSION['NOTES_FOLDER_ORDER_BY'][$folderId]) && !empty($_SESSION['NOTES_FOLDER_ORDER_BY'][$folderId])) {
 			$order_by = $_SESSION['NOTES_FOLDER_ORDER_BY'][$folderId];
 		} else {
 			$order_by = ($use_default_order_by);
diff --git a/modules/Documents/views/FilePreview.php b/modules/Documents/views/FilePreview.php
index 893cdf70646e9619a98e76e2a4d267e5620511ac..1021819e57fb73c1193d345b6801a99bb12f4525 100644
--- a/modules/Documents/views/FilePreview.php
+++ b/modules/Documents/views/FilePreview.php
@@ -55,7 +55,10 @@ class Documents_FilePreview_View extends Vtiger_IndexAjax_View {
 				}
 			}
 		}
-
+		$fileDetails['path'] = isset($fileDetails['path']) ? $fileDetails['path'] : "";
+		$fileDetails['attachmentsid'] = isset($fileDetails['attachmentsid']) ? $fileDetails['attachmentsid'] : "";
+		$fileDetails['name'] = isset($fileDetails['name']) ? $fileDetails['name'] : "";
+		$fileDetails['type'] = isset($fileDetails['type']) ? $fileDetails['type'] : "";
 		$path = $fileDetails['path'].$fileDetails['attachmentsid'].'_'.$fileDetails['name'];
 		$type = $fileDetails['type'];
 		$contents = $fileContent;
diff --git a/pkg/vtiger/modules/ModComments/layouts/v7/modules/ModComments/FilePreview.tpl b/pkg/vtiger/modules/ModComments/layouts/v7/modules/ModComments/FilePreview.tpl
index c11c208a7f7f1127c36c32b2b56cdac66e99ea16..f3dc9dfd7515da689a920897d0409d57f184ab12 100644
--- a/pkg/vtiger/modules/ModComments/layouts/v7/modules/ModComments/FilePreview.tpl
+++ b/pkg/vtiger/modules/ModComments/layouts/v7/modules/ModComments/FilePreview.tpl
@@ -11,10 +11,10 @@
         <div class="modal-content">
             <div class="filePreview container-fluid">
                 <div class="modal-header row">
-                    <div class="filename {if $FILE_PREVIEW_NOT_SUPPORTED neq 'yes'} col-lg-8 {else} col-lg-11 {/if}">
+                    <div class="filename {if isset($FILE_PREVIEW_NOT_SUPPORTED) && $FILE_PREVIEW_NOT_SUPPORTED neq 'yes'} col-lg-8 {else} col-lg-11 {/if}">
                         <h4 class="textOverflowEllipsis maxWidth50" title="{$FILE_NAME}"><b>{$TRIMMED_FILE_NAME}</b></h4>
                     </div>
-                    {if $FILE_PREVIEW_NOT_SUPPORTED neq 'yes'}
+                    {if isset($FILE_PREVIEW_NOT_SUPPORTED) && $FILE_PREVIEW_NOT_SUPPORTED neq 'yes'}
                         <div class="col-lg-3">
                             <a class="btn btn-default btn-small pull-right marginTop5px" href="{$DOWNLOAD_URL}">{vtranslate('LBL_DOWNLOAD_FILE',$MODULE_NAME)}</a>
                         </div>
@@ -26,7 +26,7 @@
                     </div>
                 </div>
                 <div class="modal-body row" style="height:550px;">
-                    {if $FILE_PREVIEW_NOT_SUPPORTED eq 'yes'}
+                    {if isset($FILE_PREVIEW_NOT_SUPPORTED) && $FILE_PREVIEW_NOT_SUPPORTED eq 'yes'}
                         <div class="well" style="height:100%;">
                             <center>
                                 <b>{vtranslate('LBL_PREVIEW_NOT_AVAILABLE',$MODULE_NAME)}</b>
@@ -43,15 +43,15 @@
                             </center>
                         </div>
                     {else}
-                        {if $BASIC_FILE_TYPE eq 'yes'}
+                        {if isset($BASIC_FILE_TYPE) && $BASIC_FILE_TYPE eq 'yes'}
                             <div style="overflow:auto;height:100%;">
                                 <pre>
                                     {htmlentities($FILE_CONTENTS)}
                                 </pre>
                             </div>
-                        {else if $OPENDOCUMENT_FILE_TYPE eq 'yes'}
+                        {else if isset($OPENDOCUMENT_FILE_TYPE) && $OPENDOCUMENT_FILE_TYPE eq 'yes'}
                             <iframe id="viewer" src="libraries/jquery/Viewer.js/#../../../{$DOWNLOAD_URL}" width="100%" height="100%" allowfullscreen webkitallowfullscreen></iframe>
-                        {else if $PDF_FILE_TYPE eq 'yes'}
+                        {else if isset($PDF_FILE_TYPE) && $PDF_FILE_TYPE eq 'yes'}
                             <iframe id='viewer' src="libraries/jquery/pdfjs/web/viewer.html?file={$SITE_URL}/{$DOWNLOAD_URL|escape:'url'}" height="100%" width="100%"></iframe>
                         {else if $IMAGE_FILE_TYPE eq 'yes'}
                             <div style="overflow:auto;height:100%;width:100%;float:left;background-image: url({$DOWNLOAD_URL});background-color: #EEEEEE;background-position: center 25%;background-repeat: no-repeat;display: block; background-size: contain;"></div>