Fantastical not working: what to check, in order

Fantastical rarely breaks in a dramatic way. A client meeting shows up in Calendar but not in Fantastical. The iPhone shows an event the Mac never received. An alert fires twice, or not at all. The instinct is to delete the app and start again, and that is usually the slowest route, because most of these problems are not stored in the app that would be deleted.

This guide sorts the common failures into a sequence, cheapest check first, using what Flexibits publishes in its FAQ, help book and support articles. The aim is to reach the actual cause in a few minutes and avoid a full reset unless nothing else works.

Where a Fantastical problem can live

It helps to know that Fantastical keeps its state in three separate places. A fix applied in the wrong place changes nothing.

Layer	What it holds	Typical symptom when it is wrong
Calendar account (iCloud, Google, Microsoft 365, Exchange)	The events themselves	Event missing everywhere, including the web
Flexibits Account	Subscription status, calendar sets, templates, some notification state	Premium on one device, free on another; sets not matching
macOS	Privacy permissions and system notification settings	Local calendars missing, alerts silent or doubled

Fantastical is a client. It reads and writes events that sit on a server owned by Apple, Google or Microsoft. If an event is not on that server, no calendar app will show it. If it is on the server and Fantastical does not show it, the problem is in the second or third layer.

Update before diagnosing anything. The Mac release notes list version 4.1.17 on July 21, 2026, 4.1.18 on August 14 and 4.1.19 on September 1. Those three releases include improved sync reliability for shared iCloud calendars, a fix for Microsoft 365 calendars disappearing when Microsoft 365 is overloaded, a fix for duplicate mirrored events, and a fix for a sync error when deleting or declining an Outlook event that had already been removed. A bug fixed six weeks ago can look exactly like a configuration mistake.

The two minute test that splits the problem in half

Flexibits' own sync troubleshooting article recommends a test that tells you which layer to look at. Open the web version of the account in question: iCloud.com for iCloud, calendar.google.com for Google, or Outlook on the web for Exchange and Microsoft 365. Create a new test event there. Then watch every device running Fantastical.

• The event appears on every device. The accounts are connected correctly. The likely culprit is the default calendar, meaning events created in Fantastical are going to a different calendar than expected.
• The event appears on some devices only. The devices that miss it are misconfigured. Check the account setup on those specific devices.
• The event never reaches Fantastical, and the original event is also missing on the web. The problem sits upstream, with the app or person that created the event, not with Fantastical.

The same article notes that syncing can take a few minutes, so give the test event a little time before drawing a conclusion. It is also worth a glance at status.flexibits.com, the vendor's status page, to rule out a service side incident. At the time of writing it reported no problems detected.

Events in Apple Calendar but not in Fantastical

This is one of the first troubleshooting questions in the Flexibits FAQ, and the answer surprises people who assume Fantastical borrows the accounts set up in macOS.

If you use a service such as iCloud, Google, Microsoft 365, or Exchange, you need to add that account directly to Fantastical. Source: flexibits.com

Work through these in order:

1. Settings, Accounts. Is the account that holds the missing events listed? If not, add it with the plus button.
2. Settings, Calendars & Lists. Is the specific calendar enabled?
3. View menu, Calendar Sets. Is the right set active? A set built for work hides personal calendars by design, which reads as missing data.
4. On My Mac calendars. Local calendars need two things: Fantastical must be allowed to access Calendars and Reminders under Privacy & Security in System Settings, and local calendar sync must be on under Settings, Accounts, Apps. The FAQ states that Fantastical will not work if access to either is refused. Birthdays and invitations also need access to Contacts.

Calendar sets deserve a note of their own. According to the Flexibits pricing page, the free tier includes one calendar set, while Premium allows unlimited sets. Anyone who built several sets during a trial and then dropped back to free should expect the set picker to look different afterwards.

Version 4.1.18 also added an option to show calendars and task lists from macOS Internet Accounts. For someone who wants to keep account setup in System Settings, that option, rather than re-adding every account, is the thing to look for after updating.

The Mac and the iPhone disagree

Cross device mismatches usually come down to three settings that must match on every device. The Flexibits troubleshooting article lists them in this order.

Same accounts

Every device needs the same calendar accounts added inside Fantastical. On iPhone and iPad this is under Settings, then Accounts, reached from the menu icon in the upper left. On Windows it sits under File, Settings, Accounts.

Same visible calendars and set

The same calendars enabled, and the same calendar set active. On iOS the active set is shown at the top of Calendars & Lists with a checkmark.

Same default calendar

This is the one that produces the most confusing symptom. If the Mac's default calendar is a Google calendar and the iPhone's default is an iCloud calendar, events typed on the Mac land in Google and events typed on the phone land in iCloud. Nothing is lost, but each device appears to hold events the other lacks. Check the default calendar in General settings, and then check it again per calendar set, because each set can carry its own default.

A split Flexibits Account

A separate cause explains the "Premium on the Mac, free on the phone" report. The getting started guide warns that signing in on a second device with a different method than the original one creates a second account.

If you don't use the same sign in method, you will end up with multiple accounts which cause sync and subscription problems. Source: flexibits.com

The three methods are email and password, Sign in with Apple, and Sign in with Google. The fix is to sign out on the odd device and sign back in with the original method. Devices that do not share the same iCloud account will also ask for the account key shown at sign up, which can be viewed in Settings on any device already signed in.

An account refuses to connect

Connection failures are mostly rules set by the account provider rather than faults in the app.

iCloud. Fantastical cannot use the normal Apple Account password. Generate an app-specific password at account.apple.com under Sign-In and Security, and paste that in. The FAQ adds two conditions: two-factor authentication must be turned on, and the email entered must be the Apple Account's primary address. The primary address can be confirmed at account.apple.com before trying again.

Google Workspace. Some organizations restrict third-party apps. When that is the case, nothing on the user's side will help, and a Workspace admin has to mark Fantastical as a trusted app.

Microsoft 365. The help book recommends adding the account as Microsoft 365 rather than as Exchange, so that the organization's single sign-on and multi-factor authentication work. It also publishes an admin consent link for organizations that block third-party apps by default.

A limitation that looks like a bug. Fantastical now syncs Microsoft 365 through Microsoft Graph, and the help book is explicit that Graph sync does not support delegated calendars. Shared calendars that have been added to the account in Outlook on the web should still appear. An executive assistant who manages a manager's calendar through delegation will see that calendar missing, and no amount of re-adding the account changes it.

Alerts are silent or arrive twice

Double alerts happen when both Apple Calendar and Fantastical are delivering notifications for the same events. Silent alerts happen when macOS is blocking Fantastical. The FAQ gives a three step fix that covers both.

1. In Fantastical Settings, open Alerts and confirm the notification types wanted are enabled.
2. In macOS System Settings, open Notifications and turn off every option for Calendar and Reminders, including setting the alert style to None.
3. In the same place, confirm all notification options are enabled for both Fantastical and Fantastical Helper.

Step two stops the duplicates. Step three is what brings back silent alerts, and Fantastical Helper is easy to overlook because it is not something anyone launches directly.

To mute one noisy calendar, such as a subscribed sports schedule, double-click it in Settings, Calendars & Lists and tick Ignore alerts. Messages about changes to shared calendars have their own checkbox under Alerts.

Time to leave alerts follow separate rules, set out in the travel time help page. They are based on the Mac's current location and only appear within three hours of the next event's location. The location also has to be picked from the suggestion list. Typing an address and moving on means no time to leave alert.

Fantastical quits or will not open

When Fantastical quits without a crash dialog, Flexibits points first to free disk space. Its support article explains that macOS may delete app files when storage runs low, and terminates the app to prevent data corruption. The example given is a system with around 20 GB free. Some disk "cleaner" utilities can trigger the same behaviour.

If crashes on launch or vanished accounts persist, the FAQ documents a reset:

1. In Finder, press Command, Shift and G, go to ~/Library/Containers, and move the Fantastical folder to the Trash.
2. Do the same in ~/Library/Group Containers with the folder 85C27NK92C.com.flexibits.fantastical2.mac.
3. Restart the Mac, open Fantastical, and set up accounts again.

The restart is not optional. The FAQ warns that settings will not save if the Mac is not restarted after deleting the folders. Treat this as the last step, since it means generating new app-specific passwords and repeating any organizational approval.

Before contacting Flexibits

If the problem survives all of the above, support will want a diagnostics report from each device. On the Mac, choose Help in the menu bar, then Diagnostics & Troubleshooting, then Copy Report. The same option exists under Help in the iOS settings and in the Windows menu. Sending a report from a device that works alongside one that does not makes the mismatch easier to spot.

A few facts are worth having in hand at this stage:

• Old macOS. Fantastical 3.8.23 is listed as the last version for macOS Big Sur. Support for Fantastical 2 ended in 2020.
• Trials. Flexibits Premium includes a 14 day free trial. To avoid renewal, cancel at least 24 hours before it ends. Charges already billed are non-refundable. App Store subscriptions are cancelled in the App Store; direct subscriptions in the Flexibits Account billing page.
• Vendor status. As of September 2026 there is no announced shutdown or stop on new sign-ups, the Mac App Store seller is still Flexibits Inc., and the most recent pricing change took effect on January 3, 2023.

When sync is fixed but the week still does not work

Once events appear, match across devices and alert once, a different problem often becomes visible. The calendar is accurate, but it is not realistic. A meeting ends at 10:00, the next one starts at 10:30 across town, and the grid shows thirty free minutes that do not exist once a forty minute journey is counted. Colleagues viewing a shared calendar see the same false gap and book into it.

That is a planning problem rather than a sync problem, and no amount of troubleshooting touches it. The travel time guide describes placing the journey itself on the calendar so the visible gaps match the real ones, and entering events covers turning a plain sentence into a timed block quickly enough that it actually gets done.

What to change first

Update Fantastical, run the web test to find out which layer is wrong, and fix only that layer. If sync turns out to be healthy and the real friction is building a realistic day, compare options on Compared with other calendars, where a calendar app for Mac such as Caltimate is set out alongside the alternatives.