Outlook Fix · All Versions
Outlook calendar appointments disappearing
If appointments keep vanishing from your Outlook calendar, don't panic — they're usually still there, just hidden by a view filter, sitting in a different calendar, or waiting behind a corrupt local cache. Here's how to find them and stop it happening again. Rated 4.9 on Google.
- ● Windows & Android
- ● Microsoft Partner
- ● Fixed remotely in minutes
Do this first
Check Outlook on the web before anything else
The single most useful thing you can do is open Outlook on the web (sign in at the Microsoft 365 / Outlook.com site) and look at the calendar there. Because the web version reads straight from Microsoft's servers, it tells you the truth. If your appointments are present on the web, they haven't been deleted — the problem is on your PC's Outlook, and it's a display or cache issue we can clear in minutes with nothing lost. If they're gone from the web too, they've genuinely been removed, and we shift to recovering them.
This one check saves a huge amount of worry, because it separates "Outlook is hiding them" from "something deleted them" — two very different fixes.
// NEED THIS FIXED RIGHT NOW?
Skip the DIY — call 01202 775566 and we can be looking at your screen within minutes. You watch everything we do, and most problems on this page are fixed in one short remote session. (Mon–Fri, 9am–5pm.)
The real causes
Why appointments vanish — and how to fix each
A view filter or the wrong calendar. The most common cause is completely harmless: a filter has been applied to the calendar view, or you're looking at a different calendar from the one the appointments live in. In classic Outlook the cure is to reset the view — close Outlook and reopen it with outlook.exe /cleanviews (Windows key + R, paste that, Enter). That strips any custom filters and puts every appointment back on screen; it changes only how items are displayed and never touches the appointments themselves. Also check the calendar list on the left so you're viewing the right one. (The /cleanviews switch is a classic-Outlook tool; in the new Outlook for Windows, remove any filter via the calendar view options instead.)
A corrupt cached OST file. Microsoft 365 and Exchange accounts keep a local copy of your mailbox in an .ost file. If that copy corrupts, appointments can flicker or drop out — even though they're safe on the server. The fix is to close Outlook, delete (or rename) the .ost, and reopen Outlook: it rebuilds a fresh copy straight from the server, so nothing is lost. This is safe for Exchange/365 accounts only — never do it to a POP account, whose mail lives only in the local file. It's the sort of thing we're happy to do with you over remote support so you're comfortable.
A phone, app or delegate deleting them. If someone has delegate access to your calendar, or a phone app is misbehaving, appointments can be genuinely deleted. Check the calendar's permissions and any linked mobile apps. And if your organisation has a retention policy, older items may be removed automatically on a schedule — an admin setting rather than a fault.
FAMILY-RUN SINCE 1995 · ★ 4.9 ON GOOGLE · 200+ COMPUTERS UNDER OUR CARE · NO FIX, NO FEE · SAME-DAY REMOTE SUPPORT
// GOOD QUESTIONS
Frequently asked
My appointments vanished — are they gone for good?
Usually not. First open Outlook on the web and check the calendar there, because it reads straight from the server. If the appointments are present on the web, they're safe and the problem is just your PC's Outlook hiding them — a quick fix. If they're missing on the web too, they've been genuinely deleted and we move to recovering them, often still possible from Deleted Items or a server backup.
What does outlook.exe /cleanviews do — is it safe?
It's completely safe. It resets your Outlook views back to default, removing any custom filters or groupings that might be hiding appointments. It doesn't touch your actual data — only how it's displayed. Press Windows key + R, type outlook.exe /cleanviews and press Enter. Note it's a switch for classic Outlook; the new Outlook for Windows doesn't use command-line switches, so you clear filters from the calendar view options there instead.
Will deleting the OST file lose my calendar?
No — as long as it's a Microsoft 365 or Exchange account. The OST is only a local cached copy of that mailbox, and the real data lives on Microsoft's servers. When you close Outlook, delete or rename the OST and reopen, Outlook downloads a fresh copy from the server. This is a standard fix for a corrupt cache and nothing is lost. Never do this to a POP account, though — POP mail is stored only in the local file, so deleting it would lose mail.
Could my phone or someone else be deleting appointments?
Yes, it happens. A misbehaving mobile app can delete items during a sync, and anyone with delegate access to your calendar can remove appointments too. Check your calendar's sharing permissions and any linked phone apps. If items keep going on a schedule, it may be an organisation retention policy set by your admin rather than a person.
Only some appointments disappear, not all — why?
That points to a view filter (which hides items matching certain criteria) or a category/recurring-meeting quirk, rather than deletion. In classic Outlook reset the view with outlook.exe /cleanviews and make sure no filter is applied via the View tab > View Settings > Filter. If specific recurring meetings vanish, the organiser may have changed or cancelled the series.
Can 365 Techies recover missing appointments remotely?
Yes. Call 01202 775566 — we'll phone you first, then connect to your screen over Splashtop so you can watch. We'll check the web calendar, reset views, safely rebuild a corrupt cache if needed, and recover deleted items where possible. It's usually sorted in minutes and access ends the moment we're done.
Appointments still missing?
Call 365 Techies on 01202 775566. We'll phone you first, connect over Splashtop while you watch, and track down your appointments — safely, nothing lost — usually in minutes.
01202 775566 · help@365techies.co.uk · MON–FRI 9AM–5PM