Error 8500201D is an old and constant error that has been plaguing users of Windows phone for years. This error prevents users from syncing contacts, emails and calendar events. It affect as Windows Phone 8.1 users, as well as users of Windows 10 Mobile. This error also can start to occur after Outlook.com account updating.
Right now, this error is not investigated and its possible causes can be:
- The 8500201D error may be caused by either a mailformed item, or an item with an attachment that is too big for the phone to handle;
- The logs are not available on production-version devices.
In case you are seeing 8500201D error, you can notice that:
- All contacts you had pinned disappeared from the home screen of your phone
- In Settings -> Emails and Accounts you can see, that your Outlook account is not synchronized. In case you are trying to sync it manually, you are getting the 8500201D error again;
- Photos in phone contacts also disappeared;
- Notification sounds also disappeared and/or changed etc.
Some solutions to fix 8500201D error
Right now there is no best solution on how to fix this error. It’s a fact that Microsoft team knows and works on that error. Microsoft employees is aware of this issue and it is under investigation right now (details on this page).
In the list above, we are sharing all known methods, that helped different users to sync their devices successfully after 8500201D error:
1. Enable using POP
The first solution is to try to enable using POP. You need to log into your Outlook webmail and go to Settings > Options. Under Mail, you need to choose Accounts, then POP and IMAP. Click Yes on Let devices and apps that is using POP, after that save the changes. Restart your phone and then try syncing it again.
2. Remove your device from Outlook.com and then try sync it again
The other method is to remove your phone from Outlook.com and then try to sync it again. Removing this partnership is often fixes all the sync issues. After that, you can still get some troubles with incorrectly linked contacts, problems with duplicates and triplicates for the same contact, but otherwise this solution works good.
To remove device partnership follow these steps:
- Sign in to Outlook.
- Choose Settings next to your name in the upper-right corner of the page, then click on Options.
- In the left navigation bar, under General, choose Mobile Devices.
- Select your phone in the list, and then select Remove to delete the device partnership.
- Select Yes in the confirmation box.
If you only want to remove this device from the list, stop here. If you’re attempting to fix a sync issue, continue with the remaining steps below.
- Go to your mobile device and power it off completely.
- Restart your mobile device after a few seconds, and then sync your mailbox again.
3. Clear up your calendar events
Some of the users had success with clearing up events in their calendar (events scheduled in CT that did not convert properly to ET). To do that you need to delete individual (or a recuring series) calendar events, then re-syncing it and see if it helped. In case you delete an event and it turns out it was clean (it wasn’t the cause of the problem), you can easily re-instate the event by undeleting it. The other solution is to remove the Calendar and only sync the email and contacts to the device, but this can help you only if you are getting an error while syncing Calendar only (and your Contacts and Mails is OK).
4. Perform a hard-reset of your device
The last one method is to try to perform a hard-reset, which will most likely delete all the items that failed syncing — expect to lose a lot of contacts, calendars, SMS and MMS backup etc. Till now this is the most well-known solution to fix 8500201D error.
That’s all! Please, feel free to list the troubleshooting steps in the comment section in case you have another successful method to fix error 500201D. Hope this was useful!