diff --git a/backend/routers/local_router.py b/backend/routers/local_router.py
index 8454fd5..3feff58 100644
--- a/backend/routers/local_router.py
+++ b/backend/routers/local_router.py
@@ -15,6 +15,7 @@ import permissions
 from auth import get_current_user
 from database import get_db
 from local_events_util import build_local_event_dict, resolve_creator
+from urllib.parse import quote
 
 router = APIRouter()
 
@@ -839,9 +840,20 @@ def export_calendar(
         atts = attachments_store.by_event(db, [e.id for e in events])
     ics = ical_io.build_ics(cal, events, name_cache=name_cache,
                             attachments_by_event=atts, base_url=base_url)
-    safe_name = "".join(c for c in cal.name if c.isalnum() or c in (" ", "-", "_")).strip() or "calendar"
+    # RFC 6266, the same way attachments_router already does it: str.isalnum()
+    # is true for "ö", so without an explicit ASCII test the "safe" name carries
+    # the very bytes it exists to avoid — a raw umlaut in an HTTP header, which
+    # a reverse proxy rejects outright. That is what made exporting a calendar
+    # called "Persönlich" fail with no usable error.
+    ascii_name = "".join(
+        c for c in cal.name if c.isascii() and (c.isalnum() or c in " -_")
+    ).strip() or "calendar"
+    disposition = (
+        f'attachment; filename="{ascii_name}.ics"; '
+        f"filename*=UTF-8''{quote(cal.name + '.ics')}"
+    )
     return Response(
         content=ics,
         media_type="text/calendar",
-        headers={"Content-Disposition": f'attachment; filename="{safe_name}.ics"'},
+        headers={"Content-Disposition": disposition},
     )
diff --git a/frontend/js/api.js b/frontend/js/api.js
index a080b42..8061469 100644
--- a/frontend/js/api.js
+++ b/frontend/js/api.js
@@ -86,8 +86,13 @@ async function downloadRequest(path, fallbackName) {
     return null;
   }
   if (!res.ok) {
-    const err = await res.json().catch(() => ({ detail: t('unknown_error') }));
-    const e = new Error(err.detail || `HTTP ${res.status}`);
+    // A non-JSON body means the failure happened outside the app — a reverse
+    // proxy rejecting the response, say. Showing "unknown error" there hides
+    // the one clue there is, so fall back to the body text and the status.
+    const raw = await res.text().catch(() => '');
+    let detail = '';
+    try { detail = JSON.parse(raw).detail || ''; } catch { detail = raw.trim().slice(0, 200); }
+    const e = new Error(detail || t('unknown_error') + ' (HTTP ' + res.status + ')');
     // Keep the status so callers can map it to a translated message instead of
     // showing the backend's German detail to someone running the app in Finnish.
     e.status = res.status;
diff --git a/frontend/js/calendar.js b/frontend/js/calendar.js
index bb048d4..3175f91 100644
--- a/frontend/js/calendar.js
+++ b/frontend/js/calendar.js
@@ -4383,7 +4383,7 @@ function initResizableCalTable(table) {
   // Lock to px + fixed layout so dragging one column doesn't reflow the others.
   // Sensible defaults per column (Name / Herkunft / Sichtbar / Benachrichtigungen
   // / Export-Import / Sync / trash); user drags override and persist.
-  const DEFAULTS = [200, 90, 80, 150, 240, 90, 44];
+  const DEFAULTS = [200, 90, 80, 150, 300, 90, 44];
   ths.forEach((th, i) => {
     const w = (Array.isArray(saved) && saved[i]) ? saved[i]
             : (DEFAULTS[i] || th.offsetWidth || 100);
@@ -4458,7 +4458,7 @@ function renderCalendarTable() {
         <button class="btn btn-ghost btn-sm" data-ct-share="${cal.id}">${t('share')}</button>
         <button class="btn btn-ghost btn-sm" data-ct-export="local" data-ct-id="${cal.id}" data-ct-name="${escHtml(cal.name)}">Export</button>
         <button class="btn btn-ghost btn-sm" data-ct-import="local" data-ct-id="${cal.id}">Import</button>
-        <button class="btn btn-ghost btn-sm ct-dav-toggle${pub ? ' on' : ''}" data-ct-dav-id="${cal.id}" data-ct-dav-on="${pub ? '1' : '0'}">${pub ? t('caldav_unpublish') : t('caldav_publish')}</button>
+        <button class="btn btn-ghost btn-sm ct-dav-toggle${pub ? ' on' : ''}" data-ct-dav-id="${cal.id}" data-ct-dav-on="${pub ? '1' : '0'}" title="${pub ? t('caldav_unpublish') : t('caldav_publish')}">CalDAV</button>
       </td>
       <td>—</td>
       <td><button class="icon-btn mini-btn" data-ct-del="local" data-ct-id="${cal.id}">${TRASH}</button></td>