diff --git a/frontend/src/App.js b/frontend/src/App.js
index 914e13ac..257e209a 100644
--- a/frontend/src/App.js
+++ b/frontend/src/App.js
@@ -28,6 +28,7 @@ import Settings from './pages/Settings';
 import StreamProfiles from './pages/StreamProfiles';
 import useAuthStore from './store/auth';
 import logo from './images/logo.png';
+import Alert from './components/Alert';
 
 // NEW: import the floating PiP component
 import FloatingVideo from './components/FloatingVideo';
@@ -110,8 +111,8 @@ const App = () => {
             flexDirection: 'column',
             ml: `${open ? drawerWidth : miniDrawerWidth}px`,
             transition: 'width 0.3s, margin-left 0.3s',
-            // height: '100vh',
             backgroundColor: '#495057',
+            height: '100%',
           }}
         >
           <Box
@@ -149,6 +150,9 @@ const App = () => {
         </Box>
       </Router>
 
+      {/* Global Snackbar for system-wide messages */}
+      <Alert />
+
       {/* Always-available floating video; remains visible across page changes */}
       <FloatingVideo />
     </ThemeProvider>
diff --git a/frontend/src/components/Alert.js b/frontend/src/components/Alert.js
new file mode 100644
index 00000000..8f625364
--- /dev/null
+++ b/frontend/src/components/Alert.js
@@ -0,0 +1,26 @@
+import React, { useState } from 'react';
+import { Snackbar, Alert, Button } from '@mui/material';
+import useAlertStore from '../store/alerts';
+
+const AlertPopup = () => {
+  const { open, message, severity, hideAlert } = useAlertStore();
+
+  const handleClose = () => {
+    hideAlert();
+  };
+
+  return (
+    <Snackbar
+      open={open}
+      autoHideDuration={3000}
+      onClose={handleClose}
+      anchorOrigin={{ vertical: 'top', horizontal: 'right' }}
+    >
+      <Alert onClose={handleClose} severity={severity} sx={{ width: '100%' }}>
+        {message}
+      </Alert>
+    </Snackbar>
+  );
+};
+
+export default AlertPopup;
diff --git a/frontend/src/components/forms/UserAgent.js b/frontend/src/components/forms/UserAgent.js
index 6f5f80c4..db13429f 100644
--- a/frontend/src/components/forms/UserAgent.js
+++ b/frontend/src/components/forms/UserAgent.js
@@ -1,5 +1,5 @@
 // Modal.js
-import React, { useEffect } from "react";
+import React, { useEffect } from 'react';
 import {
   TextField,
   Button,
@@ -9,22 +9,23 @@ import {
   DialogTitle,
   DialogContent,
   DialogActions,
-} from "@mui/material";
-import { useFormik } from "formik";
-import * as Yup from "yup";
-import API from "../../api";
+} from '@mui/material';
+import { useFormik } from 'formik';
+import * as Yup from 'yup';
+import API from '../../api';
+import useSettingsStore from '../../store/settings';
 
 const UserAgent = ({ userAgent = null, isOpen, onClose }) => {
   const formik = useFormik({
     initialValues: {
-      user_agent_name: "",
-      user_agent: "",
-      description: "",
+      user_agent_name: '',
+      user_agent: '',
+      description: '',
       is_active: true,
     },
     validationSchema: Yup.object({
-      user_agent_name: Yup.string().required("Name is required"),
-      user_agent: Yup.string().required("User-Agent is required"),
+      user_agent_name: Yup.string().required('Name is required'),
+      user_agent: Yup.string().required('User-Agent is required'),
     }),
     onSubmit: async (values, { setSubmitting, resetForm }) => {
       if (userAgent?.id) {
@@ -60,8 +61,8 @@ const UserAgent = ({ userAgent = null, isOpen, onClose }) => {
     <Dialog open={isOpen} onClose={onClose}>
       <DialogTitle
         sx={{
-          backgroundColor: "primary.main",
-          color: "primary.contrastText",
+          backgroundColor: 'primary.main',
+          color: 'primary.contrastText',
         }}
       >
         User-Agent
@@ -132,7 +133,7 @@ const UserAgent = ({ userAgent = null, isOpen, onClose }) => {
             color="primary"
             disabled={formik.isSubmitting}
           >
-            {formik.isSubmitting ? <CircularProgress size={24} /> : "Submit"}
+            {formik.isSubmitting ? <CircularProgress size={24} /> : 'Submit'}
           </Button>
         </DialogActions>
       </form>
diff --git a/frontend/src/components/tables/StreamProfilesTable.js b/frontend/src/components/tables/StreamProfilesTable.js
index b23257a8..c22d6c4b 100644
--- a/frontend/src/components/tables/StreamProfilesTable.js
+++ b/frontend/src/components/tables/StreamProfilesTable.js
@@ -30,6 +30,8 @@ import useEPGsStore from '../../store/epgs';
 import StreamProfileForm from '../forms/StreamProfile';
 import useStreamProfilesStore from '../../store/streamProfiles';
 import { TableHelper } from '../../helpers';
+import useSettingsStore from '../../store/settings';
+import useAlertStore from '../../store/alerts';
 
 const StreamProfiles = () => {
   const [profile, setProfile] = useState(null);
@@ -40,6 +42,8 @@ const StreamProfiles = () => {
   const [activeFilterValue, setActiveFilterValue] = useState('all');
 
   const streamProfiles = useStreamProfilesStore((state) => state.profiles);
+  const { settings } = useSettingsStore();
+  const { showAlert } = useAlertStore();
 
   const columns = useMemo(
     //column definitions...
@@ -112,8 +116,13 @@ const StreamProfiles = () => {
     setProfileModalOpen(true);
   };
 
-  const deleteStreamProfile = async (ids) => {
-    await API.deleteStreamProfile(ids);
+  const deleteStreamProfile = async (id) => {
+    if (id == settings['default-stream-profile'].value) {
+      showAlert('Cannot delete default stream-profile', 'error');
+      return;
+    }
+
+    await API.deleteStreamProfile(id);
   };
 
   const closeStreamProfileForm = () => {
diff --git a/frontend/src/components/tables/UserAgentsTable.js b/frontend/src/components/tables/UserAgentsTable.js
index 7271aff8..a8ecb81d 100644
--- a/frontend/src/components/tables/UserAgentsTable.js
+++ b/frontend/src/components/tables/UserAgentsTable.js
@@ -26,6 +26,8 @@ import {
 import useUserAgentsStore from '../../store/userAgents';
 import UserAgentForm from '../forms/UserAgent';
 import { TableHelper } from '../../helpers';
+import useSettingsStore from '../../store/settings';
+import useAlertStore from '../../store/alerts';
 
 const UserAgentsTable = () => {
   const [userAgent, setUserAgent] = useState(null);
@@ -34,6 +36,8 @@ const UserAgentsTable = () => {
   const [activeFilterValue, setActiveFilterValue] = useState('all');
 
   const userAgents = useUserAgentsStore((state) => state.userAgents);
+  const { settings } = useSettingsStore();
+  const { showAlert } = useAlertStore();
 
   const columns = useMemo(
     //column definitions...
@@ -108,8 +112,18 @@ const UserAgentsTable = () => {
 
   const deleteUserAgent = async (ids) => {
     if (Array.isArray(ids)) {
+      if (ids.includes(settings['default-user-agent'].value)) {
+        showAlert('Cannot delete default user-agent', 'error');
+        return;
+      }
+
       await API.deleteUserAgents(ids);
     } else {
+      if (ids == settings['default-user-agent'].value) {
+        showAlert('Cannot delete default user-agent', 'error');
+        return;
+      }
+
       await API.deleteUserAgent(ids);
     }
   };
diff --git a/frontend/src/store/alerts.js b/frontend/src/store/alerts.js
new file mode 100644
index 00000000..b51076a3
--- /dev/null
+++ b/frontend/src/store/alerts.js
@@ -0,0 +1,24 @@
+// frontend/src/store/useAlertStore.js
+import { create } from 'zustand';
+
+/**
+ * Global store to track whether a floating video is visible and which URL is playing.
+ */
+const useAlertStore = create((set) => ({
+  open: false,
+  message: '',
+  severity: 'info',
+
+  showAlert: (message, severity = 'info') =>
+    set({
+      open: true,
+      message,
+      severity,
+    }),
+
+  hideAlert: () => {
+    set({ open: false });
+  },
+}));
+
+export default useAlertStore;