Unusual calendar sync problem

Here are some additional things you can try to fix the "error 500" with your subscribed calendar:

Check the External Calendar Source:

• Contact your IT department: A "500 error" often indicates a problem on the server side. There might be a temporary glitch with the external calendar source itself. Let your IT department know about the issue and see if they are aware of any problems with the calendar server.

• Calendar source documentation: If you have access to any documentation for the external calendar system, check if there are any known sync issues or specific troubleshooting steps recommended for this error code.

Deep Dive into Your Device Settings:

• Review Sync Settings: Double-check your sync settings on all your devices (iPhone, iPad, Mac) for the external calendar. Make sure everything is enabled for one-way or two-way sync (depending on your needs) and that the correct account information is used.

• Reset Sync Data: Some devices offer the option to reset sync data for specific apps or services. This can sometimes clear up corrupted data causing sync issues. Look for options like "Reset Account" or "Reset Sync Data" within your calendar app settings on each device.

Isolate the Problem:

• Try a Different Device: If possible, try syncing the calendar with another device (another Mac, friend's phone) to see if the error persists. This can help identify if the issue is specific to your devices or something broader.

• Sync a Different Calendar: Try syncing a different external calendar (if possible) to your devices. Seeing if a different calendar syncs successfully can help narrow down if the problem is with the specific calendar source or your device settings.

Advanced Troubleshooting:

• Check Firewall/Security Software: In rare cases, firewall or security software might be interfering with the calendar sync process. Try temporarily disabling them (if safe to do so) and see if the sync works.

• Update Software: Ensure your Mac and iOS devices are all updated to the latest versions. Sometimes updates include bug fixes that address sync issues.