diff --git a/package-lock.json b/package-lock.json
index a9d1ba1..a3bb200 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -13289,15 +13289,16 @@
       }
     },
     "semantic-ui-react": {
-      "version": "0.77.2",
-      "resolved": "https://registry.npmjs.org/semantic-ui-react/-/semantic-ui-react-0.77.2.tgz",
-      "integrity": "sha512-VwxY6oGLrBO2xoJiAW/vn40GL4WGZYWxtbrHIKYE1xChTOFlDxyIULMdnuAHOTbrbOYbLQ0X7LpdvEEYmieiJw==",
+      "version": "0.80.2",
+      "resolved": "https://registry.npmjs.org/semantic-ui-react/-/semantic-ui-react-0.80.2.tgz",
+      "integrity": "sha512-1sQ8NkxoDrd2c8wM+kdZ7mz3QMEYsbM1dV7uNe4b8D9VEaHdp640Ktp9DhmyCgXIo5BqdigJcZtb0jcWWGFfQg==",
       "requires": {
-        "babel-runtime": "^6.25.0",
+        "@babel/runtime": "^7.0.0-beta.48",
         "classnames": "^2.2.5",
         "fbjs": "^0.8.16",
-        "lodash": "^4.17.4",
-        "prop-types": "^15.5.10"
+        "keyboard-key": "^1.0.1",
+        "lodash": "^4.17.10",
+        "prop-types": "^15.6.1"
       }
     },
     "semver": {
diff --git a/package.json b/package.json
index 70f87d1..9eb2f2e 100644
--- a/package.json
+++ b/package.json
@@ -30,7 +30,7 @@
     "react-dom": "^15.6.1",
     "react-joyride": "^1.11.4",
     "react-sortable-hoc": "^0.6.8",
-    "semantic-ui-react": "^0.77.2",
+    "semantic-ui-react": "^0.80.0",
     "yargs-parser": "^18.1.3"
   },
   "devDependencies": {
diff --git a/src/js/components/Preview.react.js b/src/js/components/Preview.react.js
index f10e633..e6668b0 100644
--- a/src/js/components/Preview.react.js
+++ b/src/js/components/Preview.react.js
@@ -21,7 +21,7 @@ type Props = BaseProps & { hidden: boolean };
 type State = {
   previewLoading: boolean,
   sourceLoading: boolean,
-  activeTab: number
+  activeTab: number,
 };
 
 class Preview extends React.Component<Props, State> {
@@ -53,25 +53,31 @@ class Preview extends React.Component<Props, State> {
 
   reloadPreview = debounce(() => {
     if (this.state.activeTab == 0 && this.preview != null) {
+      const generatedRules = RuleExporter.export(
+        this.props.rules,
+        this.props.settings
+      );
+      const hasRequiredField = !!(
+        generatedRules &&
+        generatedRules.rules.find(rule => rule.class === 'GlobalRule')
+      );
       this.preview.loadURL(
         'http://127.0.0.1:8105/preview.php?url=' +
           encodeURIComponent(this.props.editor.url),
-        {
-          postData: [
-            {
-              type: 'rawData',
-              bytes: Buffer.from(
-                'rules=' +
-                  encodeURIComponent(
-                    JSON.stringify(
-                      RuleExporter.export(this.props.rules, this.props.settings)
-                    )
-                  )
-              ),
-            },
-          ],
-          extraHeaders: 'Content-Type: application/x-www-form-urlencoded',
-        }
+        hasRequiredField
+          ? {
+            postData: [
+              {
+                type: 'rawData',
+                bytes: Buffer.from(
+                  'rules=' +
+                      encodeURIComponent(JSON.stringify(generatedRules))
+                ),
+              },
+            ],
+            extraHeaders: 'Content-Type: application/x-www-form-urlencoded',
+          }
+          : null
       );
     }
   }, 1000);