Tasks Error: Can't open this item

[petersie]

I get this error message periodically when I double-click a task in the Task
View. Of course the eror message is mega-helpful: "Can't open this item."
When it happens, it happens to ALL tasks in the list. The only thing that
will 'unfreeze' the tasks is a shut-down and re-start of Outlook.

 

[sadalit]

We experienced this issue too. In our case, it happened after we
applied the latest service pack to our Exchange 2003 server. There is
a hotfix for this, please see the following knowledge base article
from Microsoft:

http://support.microsoft.com/default.aspx/kb/930807/en-us

And there are some workarounds if you can't get the hotfix applied
right away:

The task email can be opened in OWA.
The task email can be opened once forwarded.

Good luck!