Item has already been added. Key in Dictionary: nnnnnnnn Key being added: nnnnnn

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Using Outlook 2007, one member of staff is plagued by this error, it occurs whenever she goes to read an email message that has previously been read.

We have checked there are no add-ins that are not meant to be there.

There are thousands of entries on the web if you Google this error, but no solutions applicable to Outlook to get rid of it.

We are not able to start Outlook in Safe mode, as our apps are delivered via Citrix. We have 3,500 other users getting Outlook via Citrix, no one else gets this error!

Any ideas?

thanks, KK

Sally Tang


Create a new Outlook profile for her to test the results.

How to Create a new Outlook Profile

Please Note: Since the web site is not hosted by Microsoft, the link may change without notice. Microsoft does not guarantee the accuracy of this information.

If the problem persists, go to File > Options > Add-ins, disable the add-ins there and check the results again.

Best Regards,

Sally Tang
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