diff --git a/workflow/engine/src/ProcessMaker/BusinessModel/WebEntry.php b/workflow/engine/src/ProcessMaker/BusinessModel/WebEntry.php
index e7c94d9f8..c30f08621 100644
--- a/workflow/engine/src/ProcessMaker/BusinessModel/WebEntry.php
+++ b/workflow/engine/src/ProcessMaker/BusinessModel/WebEntry.php
@@ -414,8 +414,7 @@ class WebEntry
                     $fileContent .= "\$_SESSION[\"CURRENT_DYN_UID\"] = \"" . $dynaFormUid . "\";\n";
                     $fileContent .= "\$G_PUBLISH = new Publisher();\n";
 
-                    $fileContent .= "G::LoadClass(\"pmDynaform\");\n";
-                    $fileContent .= "\$a = new pmDynaform(array(\"CURRENT_DYNAFORM\" => \"" . $dynaFormUid . "\"));\n";
+                    $fileContent .= "\$a = new PmDynaform(array(\"CURRENT_DYNAFORM\" => \"" . $dynaFormUid . "\"));\n";
                     $fileContent .= "if (\$a->isResponsive()) {\n";
                     $fileContent .= "    \$a->printWebEntry(\"" . $fileName . "Post.php\");\n";
                     $fileContent .= "} else {\n";
diff --git a/workflow/engine/src/ProcessMaker/BusinessModel/WebEntryEvent.php b/workflow/engine/src/ProcessMaker/BusinessModel/WebEntryEvent.php
index f362e17e4..8e80d42b9 100644
--- a/workflow/engine/src/ProcessMaker/BusinessModel/WebEntryEvent.php
+++ b/workflow/engine/src/ProcessMaker/BusinessModel/WebEntryEvent.php
@@ -456,11 +456,11 @@ class WebEntryEvent
                     $this->arrayFieldNameForException["userUid"]);
             }
 
-            if ($arrayData["WE_TYPE"] === "SINGLE" && empty($arrayData["DYN_UID"])) {
+            if ((empty($arrayData["WE_TYPE"]) || $arrayData["WE_TYPE"] === "SINGLE") && empty($arrayData["DYN_UID"])) {
                 throw new Exception(G::LoadTranslation("ID_SELECT_DYNAFORM_USE_IN_CASE"));
             }
 
-            if ($arrayData["WE_CALLBACK"] === "CUSTOM" && empty($arrayData["WE_CALLBACK_URL"])) {
+            if (isset($arrayData["WE_CALLBACK"]) && $arrayData["WE_CALLBACK"] === "CUSTOM" && empty($arrayData["WE_CALLBACK_URL"])) {
                 throw new Exception(G::LoadTranslation("ID_ENTER_VALID_URL"));
             }
         } catch (Exception $e) {
diff --git a/workflow/public_html/sysGeneric.php b/workflow/public_html/sysGeneric.php
index d7270015c..36bbd3778 100644
--- a/workflow/public_html/sysGeneric.php
+++ b/workflow/public_html/sysGeneric.php
@@ -814,6 +814,8 @@ if (substr( SYS_COLLECTION, 0, 8 ) === 'gulliver') {
             echo $message;
             die();
         } else {
+            //Backward compatibility: Preload PmDynaform for old generated webentry files.
+            class_exists('PmDynaform');
             \Bootstrap::registerMonologPhpUploadExecution('phpExecution', 200, 'Php Execution', $phpFile);
         }