How to recover calendar entries from suddenly empty Outlook.pst file?

Question

To whom it may concern:
On 7th January 2021 I noticed that the calendar that I had maintained over several years in the local Outlook.pst file on my computer was all in a sudden empty.
I had backed up the file on the day before by a simple copy operation.
The file was about 155 MB in size.
I am using MS Outlook 2016 in a local installation.
I did not make any changes to the installation or settings knowingly.
I observed that the size of the Outlook.pst file currently used by Outlook 2016 has collapsed to less than 20 MB.
I transferred the backed-up file to another computer and was able to open it with MS Outlook 2010.
Again the calendar was empty, yet under properties it showed about 25 MB of local calendar data.

I am puzzled and saddened by this. I certainly did not delete the calendar entries.

If someone reading this would know how to recover the calendar entries, from the possibly corrupt file, or another remedy I would be most grateful for advice.

Looking forward to your reply, Markus

Answer 1

Please make a copy of this 155 MB file and run the Inbox Repair Tool on it. When the Inbox Repair Tool is happy with it (you may have to run the tool several times), try opening it in Outlook 2016 using File > Open and Export > Open Outlook Data File and see if the calendar has entries.

Answer 2

Hi @mb2 ,

Agree with @HalHostetler, scanpst.exe is a commonly used tools for repairing corrupted .pst file.

By the way, what's the type of your account? POP, IMAP or Exchange? As I know, Exchange email account can sync its calendar items with the mail server. So, if you are using Exchange email account, checking your calendars on the web mail is also a necessary step.

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Answer 3

Try to see if your calendar data is in archive.

Answer 4

Dear mb2,

I understand the importance of recovering your calendar entries that suddenly disappeared from the Outlook.pst file. While there is no guaranteed solution, I can provide you with the following steps to increase your chances of recovery:

1. Verify the size and integrity of the Outlook.pst file: Make sure that the current size of the Outlook.pst file used by Outlook 2016 is less than 20 GB. You can also utilize the Inbox Repair Tool (SCANPST) provided by Microsoft to scan for any potential corruption in the file. It is advisable to create a backup of the file before initiating the repair process.
2. Check for hidden or orphaned calendar entries: Sometimes, calendar entries may still be present but not visible due to incorrect view settings or other issues. To verify this, navigate to the Calendar section in Outlook, go to the View tab, and ensure that the appropriate view (e.g., "Day," "Week," or "Month") is selected. Resetting the calendar view settings to their default values can also be attempted.
3. Attempt recovery from the backed-up file: Since you have a backup of the Outlook.pst file, try opening it on a different computer with a compatible version of Outlook, such as Outlook 2010. If the calendar still appears empty, it is possible that the corruption occurred prior to the backup creation, resulting in the loss of calendar entries in both the original and backed-up files.

It is important to work with copies of the files and keep the original files intact to prevent any further data loss during the recovery process.

While I cannot guarantee the complete recovery of your calendar entries, I genuinely hope that these suggestions prove helpful in your efforts to retrieve your valuable data. Please let me know if you need any further assistance or are stuck in any steps.