diff --git a/__test__/features/Events/EventDisplay.test.tsx b/__test__/features/Events/EventDisplay.test.tsx
index d878e95..9ae32d5 100644
--- a/__test__/features/Events/EventDisplay.test.tsx
+++ b/__test__/features/Events/EventDisplay.test.tsx
@@ -1045,6 +1045,296 @@ describe("Event Full Display", () => {
       screen.getAllByDisplayValue(new RegExp(date, "i"))[0]
     ).toBeInTheDocument();
   });
+  it("saves event and moves it when calendar is changed", async () => {
+    const spyPut = jest
+      .spyOn(eventThunks, "putEventAsync")
+      .mockImplementation((payload) => () => Promise.resolve(payload) as any);
+    const spyMove = jest
+      .spyOn(eventThunks, "moveEventAsync")
+      .mockImplementation((payload) => () => Promise.resolve(payload) as any);
+    const spyRemove = jest.spyOn(eventThunks, "removeEvent");
+
+    const day = new Date();
+    const preloadedTwoCals = {
+      user: {
+        userData: {
+          sub: "test",
+          email: "test@test.com",
+          openpaasId: "667037022b752d0026472254",
+        },
+      },
+      calendars: {
+        list: {
+          "667037022b752d0026472254/cal1": {
+            id: "667037022b752d0026472254/cal1",
+            name: "Calendar One",
+            color: "#FF0000",
+            events: {
+              event1: {
+                uid: "uid-base",
+                id: "event1",
+                title: "Test Event",
+                calId: "667037022b752d0026472254/cal1",
+                start: day.toISOString(),
+                end: day.toISOString(),
+                organizer: { cn: "test", cal_address: "test@test.com" },
+                attendee: [{ cn: "test", cal_address: "test@test.com" }],
+              },
+            },
+          },
+          "667037022b752d0026472254/cal2": {
+            id: "667037022b752d0026472254/cal2",
+            name: "Calendar Two",
+            color: "#00FF00",
+            events: {},
+          },
+        },
+        pending: false,
+      },
+    };
+
+    renderWithProviders(
+      <EventDisplayModal
+        open={true}
+        onClose={mockOnClose}
+        calId={"667037022b752d0026472254/cal1"}
+        eventId={"event1"}
+      />,
+      preloadedTwoCals
+    );
+
+    fireEvent.mouseDown(screen.getByLabelText("Calendar"));
+
+    const option = await screen.findByText("Calendar Two");
+    fireEvent.click(option);
+
+    fireEvent.click(screen.getByText("Save"));
+
+    await waitFor(() => {
+      expect(spyPut).toHaveBeenCalled();
+    });
+
+    await waitFor(() => {
+      expect(spyMove).toHaveBeenCalled();
+    });
+
+    expect(spyRemove).toHaveBeenCalled();
+  });
+
+  it("removes recurrence instances when saving an edited recurring series", async () => {
+    const spyPut = jest
+      .spyOn(eventThunks, "putEventAsync")
+      .mockImplementation((payload) => () => Promise.resolve(payload) as any);
+    const spyRemove = jest.spyOn(eventThunks, "removeEvent");
+
+    const day = new Date();
+    const preloadedRecurrence = {
+      user: {
+        userData: {
+          sub: "test",
+          email: "test@test.com",
+          openpaasId: "667037022b752d0026472254",
+        },
+      },
+      calendars: {
+        list: {
+          "667037022b752d0026472254/cal1": {
+            id: "667037022b752d0026472254/cal1",
+            name: "First Calendar",
+            color: "#FF0000",
+            events: {
+              "base/20250101": {
+                uid: "base/20250101",
+                calId: "667037022b752d0026472254/cal1",
+                title: "eventA",
+              },
+              "base/20250201": {
+                uid: "base/20250201",
+                calId: "667037022b752d0026472254/cal1",
+                title: "eventB",
+              },
+              "base/20250301": {
+                uid: "base/20250301",
+                title: "Recurring event",
+                calId: "667037022b752d0026472254/cal1",
+                start: day.toISOString(),
+                end: day.toISOString(),
+                organizer: { cal_address: "test@test.com" },
+                attendee: [{ cal_address: "test@test.com", cn: "Test" }],
+              },
+            },
+          },
+        },
+        pending: false,
+      },
+    };
+
+    renderWithProviders(
+      <EventDisplayModal
+        open={true}
+        onClose={mockOnClose}
+        calId={"667037022b752d0026472254/cal1"}
+        eventId={"base/20250301"}
+      />,
+      preloadedRecurrence
+    );
+
+    act(() => fireEvent.click(screen.getByText("Save")));
+
+    await waitFor(() => {
+      expect(spyPut).toHaveBeenCalled();
+    });
+
+    await waitFor(() => {
+      expect(spyRemove).toHaveBeenCalled();
+    });
+  });
+
+  it("InfoRow renders error style when error prop is true", () => {
+    renderWithProviders(<InfoRow icon={<span>i</span>} text="Bad" error />);
+    expect(screen.getByText("Bad")).toBeInTheDocument();
+  });
+
+  it("calls onClose from useEffect if event or calendar missing", () => {
+    renderWithProviders(
+      <EventDisplayModal
+        open={true}
+        onClose={mockOnClose}
+        calId={"nonexistent/cal"}
+        eventId={"ghost"}
+      />,
+      preloadedState
+    );
+    expect(mockOnClose).toHaveBeenCalledWith({}, "backdropClick");
+  });
+
+  it("renders error row when event has error", () => {
+    const errorState = {
+      ...preloadedState,
+      calendars: {
+        list: {
+          "667037022b752d0026472254/cal1": {
+            ...preloadedState.calendars.list["667037022b752d0026472254/cal1"],
+            events: {
+              event1: {
+                ...preloadedState.calendars.list[
+                  "667037022b752d0026472254/cal1"
+                ].events.event1,
+                error: "Something went wrong",
+              },
+            },
+          },
+        },
+        pending: false,
+      },
+    };
+
+    renderWithProviders(
+      <EventDisplayModal
+        open={true}
+        onClose={mockOnClose}
+        calId={"667037022b752d0026472254/cal1"}
+        eventId={"event1"}
+      />,
+      errorState
+    );
+
+    act(() => {
+      fireEvent.click(screen.getByText("Show More"));
+    });
+
+    expect(screen.getByText("Something went wrong")).toBeInTheDocument();
+  });
+
+  it("can remove an attendee with the close button", () => {
+    renderWithProviders(
+      <EventDisplayModal
+        open={true}
+        onClose={mockOnClose}
+        calId={"667037022b752d0026472254/cal1"}
+        eventId={"event1"}
+      />,
+      preloadedState
+    );
+
+    const removeBtn = screen.getAllByTestId("CloseIcon").pop()!;
+    fireEvent.click(removeBtn);
+
+    expect(screen.queryByText(/John/)).not.toBeInTheDocument();
+  });
+
+  it("shows more attendees when overflow, then toggles back", () => {
+    const overflowState = {
+      ...preloadedState,
+      calendars: {
+        list: {
+          "667037022b752d0026472254/cal1": {
+            ...preloadedState.calendars.list["667037022b752d0026472254/cal1"],
+            events: {
+              event1: {
+                ...preloadedState.calendars.list[
+                  "667037022b752d0026472254/cal1"
+                ].events.event1,
+                attendee: new Array(6).fill(null).map((_, i) => ({
+                  cn: `Person${i}`,
+                  cal_address: `p${i}@test.com`,
+                })),
+                organizer: { cn: "test", cal_address: "test@test.com" },
+              },
+            },
+          },
+        },
+      },
+    };
+
+    renderWithProviders(
+      <EventDisplayModal
+        open={true}
+        onClose={mockOnClose}
+        calId={"667037022b752d0026472254/cal1"}
+        eventId={"event1"}
+      />,
+      overflowState
+    );
+
+    const toggle = screen.getByText(/Show more/);
+    fireEvent.click(toggle);
+
+    expect(screen.getByText(/Show less/)).toBeInTheDocument();
+  });
+
+  it("renders video conference info when x_openpass_videoconference exists", () => {
+    const videoState = {
+      ...preloadedState,
+      calendars: {
+        list: {
+          "667037022b752d0026472254/cal1": {
+            ...preloadedState.calendars.list["667037022b752d0026472254/cal1"],
+            events: {
+              event1: {
+                ...preloadedState.calendars.list[
+                  "667037022b752d0026472254/cal1"
+                ].events.event1,
+                x_openpass_videoconference: "https://meet.test/video",
+              },
+            },
+          },
+        },
+      },
+    };
+
+    renderWithProviders(
+      <EventDisplayModal
+        open={true}
+        onClose={mockOnClose}
+        calId={"667037022b752d0026472254/cal1"}
+        eventId={"event1"}
+      />,
+      videoState
+    );
+
+    expect(screen.getByText("Video conference available")).toBeInTheDocument();
+  });
 });
 
 describe("Helper functions", () => {
diff --git a/__test__/features/Events/EventModal.test.tsx b/__test__/features/Events/EventModal.test.tsx
index c8d0db2..8aff878 100644
--- a/__test__/features/Events/EventModal.test.tsx
+++ b/__test__/features/Events/EventModal.test.tsx
@@ -247,7 +247,7 @@ describe("EventPopover", () => {
       location: "Zoom",
       organizer: { cn: "test", cal_address: "test@test.com" },
       timezone: "Europe/Paris",
-      transp: "OPAQUE",
+      transp: "TRANSPARENT",
     };
 
     // Fill inputs
diff --git a/src/features/Events/EventDisplay.tsx b/src/features/Events/EventDisplay.tsx
index 9b0027d..5bc56ab 100644
--- a/src/features/Events/EventDisplay.tsx
+++ b/src/features/Events/EventDisplay.tsx
@@ -89,13 +89,13 @@ export default function EventDisplayModal({
   );
   const [allday, setAllDay] = useState(event?.allday);
   const [repetition, setRepetition] = useState<RepetitionObject>(
-    event.repetition ?? ({} as RepetitionObject)
+    event?.repetition ?? ({} as RepetitionObject)
   );
   const [alarm, setAlarm] = useState(event?.alarm?.trigger ?? "");
-  const [busy, setBusy] = useState("");
+  const [busy, setBusy] = useState(event?.transp ?? "OPAQUE");
   const [eventClass, setEventClass] = useState(event?.class ?? "PUBLIC");
   const [timezone, setTimezone] = useState(event?.timezone ?? "UTC");
-  const [newCalId, setNewCalId] = useState(event.calId);
+  const [newCalId, setNewCalId] = useState(event?.calId);
   const [calendarid, setCalendarid] = useState(
     calId.split("/")[0] === user.userData.openpaasId
       ? userPersonnalCalendars.findIndex((cal) => cal.id === calId)
@@ -112,7 +112,7 @@ export default function EventDisplayModal({
   );
 
   const organizer =
-    event.attendee?.find(
+    event?.attendee?.find(
       (a) => a.cal_address === event?.organizer?.cal_address
     ) ?? ({} as userAttendee);
 
@@ -124,7 +124,7 @@ export default function EventDisplayModal({
     if (!event || !calendar) {
       onClose({}, "backdropClick");
     }
-    setRepetition(event.repetition ?? ({} as RepetitionObject));
+    setRepetition(event?.repetition ?? ({} as RepetitionObject));
   }, [open, eventId, dispatch, onClose, event]);
 
   if (!event || !calendar) return null;
@@ -158,7 +158,7 @@ export default function EventDisplayModal({
       organizer: event.organizer,
       timezone,
       attendee: [organizer, ...attendees],
-      transp: "OPAQUE",
+      transp: busy,
       color: userPersonnalCalendars[calendarid]?.color,
       alarm: { trigger: alarm, action: "EMAIL" },
     };
@@ -471,32 +471,32 @@ export default function EventDisplayModal({
                   setRepetition={setRepetition}
                   isOwn={isOwn}
                 />
-
-              <FormControl fullWidth margin="dense" size="small">
-                <InputLabel id="alarm">Alarm</InputLabel>
-                <Select
-                  labelId="alarm"
-                  label="Alarm"
-                  value={alarm}
-                  disabled={!isOwn}
-                  onChange={(e: SelectChangeEvent) => setAlarm(e.target.value)}
-                >
-                  <MenuItem value={""}>No Alarm</MenuItem>
-                  <MenuItem value={"-PT1M"}>1 minute</MenuItem>
-                  <MenuItem value={"-PT5M"}>2 minutes</MenuItem>
-                  <MenuItem value={"-PT10M"}>10 minutes</MenuItem>
-                  <MenuItem value={"-PT15M"}>15 minutes</MenuItem>
-                  <MenuItem value={"-PT30M"}>30 minutes</MenuItem>
-                  <MenuItem value={"-PT1H"}>1 hours</MenuItem>
-                  <MenuItem value={"-PT2H"}>2 hours</MenuItem>
-                  <MenuItem value={"-PT5H"}>5 hours</MenuItem>
-                  <MenuItem value={"-PT12H"}>12 hours</MenuItem>
-                  <MenuItem value={"-PT1D"}>1 day</MenuItem>
-                  <MenuItem value={"-PT2D"}>2 days</MenuItem>
-                  <MenuItem value={"-PT1W"}>1 week</MenuItem>
-                </Select>
-              </FormControl>
-
+                <FormControl fullWidth margin="dense" size="small">
+                  <InputLabel id="alarm">Alarm</InputLabel>
+                  <Select
+                    labelId="alarm"
+                    label="Alarm"
+                    value={alarm}
+                    disabled={!isOwn}
+                    onChange={(e: SelectChangeEvent) =>
+                      setAlarm(e.target.value)
+                    }
+                  >
+                    <MenuItem value={""}>No Alarm</MenuItem>
+                    <MenuItem value={"-PT1M"}>1 minute</MenuItem>
+                    <MenuItem value={"-PT5M"}>2 minutes</MenuItem>
+                    <MenuItem value={"-PT10M"}>10 minutes</MenuItem>
+                    <MenuItem value={"-PT15M"}>15 minutes</MenuItem>
+                    <MenuItem value={"-PT30M"}>30 minutes</MenuItem>
+                    <MenuItem value={"-PT1H"}>1 hours</MenuItem>
+                    <MenuItem value={"-PT2H"}>2 hours</MenuItem>
+                    <MenuItem value={"-PT5H"}>5 hours</MenuItem>
+                    <MenuItem value={"-PT12H"}>12 hours</MenuItem>
+                    <MenuItem value={"-PT1D"}>1 day</MenuItem>
+                    <MenuItem value={"-PT2D"}>2 days</MenuItem>
+                    <MenuItem value={"-PT1W"}>1 week</MenuItem>
+                  </Select>
+                </FormControl>
                 <FormControl fullWidth margin="dense" size="small">
                   <InputLabel id="Visibility">Visibility</InputLabel>
                   <Select
@@ -513,6 +513,19 @@ export default function EventDisplayModal({
                     <MenuItem value={"PRIVATE"}>Private</MenuItem>
                   </Select>
                 </FormControl>
+                <FormControl fullWidth margin="dense" size="small">
+                  <InputLabel id="busy">is Busy</InputLabel>
+                  <Select
+                    labelId="busy"
+                    value={busy}
+                    disabled={!isOwn}
+                    label="is busy"
+                    onChange={(e: SelectChangeEvent) => setBusy(e.target.value)}
+                  >
+                    <MenuItem value={"TRANSPARENT"}>Free</MenuItem>
+                    <MenuItem value={"OPAQUE"}>Busy </MenuItem>
+                  </Select>
+                </FormControl>
                 {/* Error */}
                 {event.error && (
                   <InfoRow
diff --git a/src/features/Events/EventModal.tsx b/src/features/Events/EventModal.tsx
index dcd0e6d..94aa481 100644
--- a/src/features/Events/EventModal.tsx
+++ b/src/features/Events/EventModal.tsx
@@ -76,7 +76,7 @@ function EventPopover({
   const [attendees, setAttendees] = useState<userAttendee[]>([]);
   const [alarm, setAlarm] = useState("");
   const [eventClass, setEventClass] = useState("PUBLIC");
-  const [busy, setBusy] = useState("");
+  const [busy, setBusy] = useState("OPAQUE");
 
   const [timezone, setTimezone] = useState(
     Intl.DateTimeFormat().resolvedOptions().timeZone
@@ -115,7 +115,7 @@ function EventPopover({
           cutype: "INDIVIDUAL",
         },
       ],
-      transp: "OPAQUE",
+      transp: busy,
       color: userPersonnalCalendars[calendarid]?.color,
       alarm: { trigger: alarm, action: "EMAIL" },
     };
@@ -326,6 +326,18 @@ function EventPopover({
                   <MenuItem value={"PRIVATE"}>Private</MenuItem>
                 </Select>
               </FormControl>
+              <FormControl fullWidth margin="dense" size="small">
+                <InputLabel id="busy">is Busy</InputLabel>
+                <Select
+                  labelId="busy"
+                  value={busy}
+                  label="is busy"
+                  onChange={(e: SelectChangeEvent) => setBusy(e.target.value)}
+                >
+                  <MenuItem value={"TRANSPARENT"}>Free</MenuItem>
+                  <MenuItem value={"OPAQUE"}>Busy </MenuItem>
+                </Select>
+              </FormControl>
             </>
           )}
         </CardContent>
diff --git a/src/features/Events/eventUtils.ts b/src/features/Events/eventUtils.ts
index 7326688..0d62ce8 100644
--- a/src/features/Events/eventUtils.ts
+++ b/src/features/Events/eventUtils.ts
@@ -157,7 +157,7 @@ export function calendarEventToJCal(
       ["summary", {}, "text", event.title ?? ""],
     ],
   ];
-  if (event.alarm) {
+  if (event.alarm?.trigger) {
     const valarm = [
       ["trigger", {}, "duration", event.alarm.trigger],
       ["action", {}, "text", event.alarm.action],