I also have this problem except when I open my calendar the item that I am
being reminded of is not there. I get the same message about parameter
values are not valid, but do not know where the item came from. I can't open
it or dismiss it. If I try to set the reminder to 2 weeks, it comes up again
in about 5 minutes.

"Brian Tillman" wrote:

Patrick H wrote:

/thanks for the speedy response. I'll try to be more precise.
The /CleanReminders switch will work in opening Outlook, but the
problem remains in that when I open my Calendar, it pops up the
Reminder window, with two appointments from the past, both of them
overdue.
When I click to dismiss each of the appointments, I get the message
"Cannot turn off the reminder. You may be reminded again. Could not
complete the operation. One or more parameter values are not valid"
I click OK and then the appt is dismissed. However when I close and
re-open Outlook, the same thing happens.
I have created a new profile and also run Detect and Repair, but the
problem persists each time I close and then open Outlook.

Since these are reminders are for past events, have you deleted the events?

It may be time to start with a new PST and copy the data over from the old.
--
Brian Tillman