I am running Outlook 2007 in an exchange 2003 environment. For 2 of the
shared calendars I access, most times I try to display them, I get an error
that says "The messaging interface has returned an unknown error. If the
problem persists, restart outlook." It doesn't fail 100% of the time, but it
does usually fail. I have access to 5 other calendars that work fine. I
double-checked the permissions on the 2 that work, and I have author-level
permissions. The affected calendars display properly for other users in the
office who are running outlook 2003.

I've seen the error on the knowledge base with regards to printing a shared
calendar, but not for simply displaying them, as I am trying to do. Anybody
have any insights?

Anybody have any thoughts?

"Trumpeter" wrote:

I am running Outlook 2007 in an exchange 2003 environment. For 2 of the
shared calendars I access, most times I try to display them, I get an error
that says "The messaging interface has returned an unknown error. If the
problem persists, restart outlook." It doesn't fail 100% of the time, but it
does usually fail. I have access to 5 other calendars that work fine. I
double-checked the permissions on the 2 that don't work, and I have author-level
permissions. The affected calendars display properly for other users in the
office who are running outlook 2003.

I've seen the error on the knowledge base with regards to printing a shared
calendar, but not for simply displaying them, as I am trying to do. Anybody
have any insights?

I have a same proble Trumpeter has. I have Outlook 2007 in an exchange 2003,
too. Generally, outlook works well, but sometimes that message just pops up
and bother me. After restart, it works ok which make me crazy again. I
checked the permissions as Trumpeter did, but it didn't help me.
Do you guys think it is kind of bugs of new software or just Trumpeter and I
have a unique problem?
If you guys know about this bad situation, please let me know

"Trumpeter" wrote:

Anybody have any thoughts?

"Trumpeter" wrote:

I am running Outlook 2007 in an exchange 2003 environment. For 2 of the
shared calendars I access, most times I try to display them, I get an error
that says "The messaging interface has returned an unknown error. If the
problem persists, restart outlook." It doesn't fail 100% of the time, but it
does usually fail. I have access to 5 other calendars that work fine. I
double-checked the permissions on the 2 that don't work, and I have author-level
permissions. The affected calendars display properly for other users in the
office who are running outlook 2003.

I've seen the error on the knowledge base with regards to printing a shared
calendar, but not for simply displaying them, as I am trying to do. Anybody
have any insights?

My company is having this same issue. We recently upgraded all users
from Office 2003 to 2007.

This first started with just two computers but little by little more
users are experiencing the problem.

When someone clicks on a shared calendar they get an error saying "The
Messaging interface returned an unknow error, if the problem persists
restart outlook"
After restarting outlook it goes away but only for a little while.

We have tried to repair and also reinstall office 2007 on the machine
to no avail. All permissions are OK. Not sure if this is an exchange
problem or an outlook issue.

Just wanted to join the chorus, am experiencing the exact same
problem. Outlook 2007 vs. Exchange 2003 - shared calendars randomly
give me an:

"The Messaging interface returned an unknow error, if the problem
persists
restart outlook"

Have anyone found a solution?

Stefan Nielsen

I am having the same problem. It is random as to whose calendar I will
receive this same error when I click on it. I have people using Outlook 2003
and 2007 and this error is not prejudiced. Close/re-open of Outlook does not
resolve. If I close Outlook and go into Task Manager, I see Outlook.exe
running and I select End Task. Upon re-opening Outlook it then works
appropriately.

I have also posted another thread specific to shared calendars not always
saving upon close/re-open of Outlook. Sometimes they are all there,
sometimes they are not, and sometimes just some of them show. I'll bet this
has something to do with this as well.

"Trumpeter" wrote:

I am running Outlook 2007 in an exchange 2003 environment. For 2 of the
shared calendars I access, most times I try to display them, I get an error
that says "The messaging interface has returned an unknown error. If the
problem persists, restart outlook." It doesn't fail 100% of the time, but it
does usually fail. I have access to 5 other calendars that work fine. I
double-checked the permissions on the 2 that work, and I have author-level
permissions. The affected calendars display properly for other users in the
office who are running outlook 2003.

I've seen the error on the knowledge base with regards to printing a shared
calendar, but not for simply displaying them, as I am trying to do. Anybody
have any insights?

I have reproduced this problem (where all shared calendars exhibit this
behavior) by having Outlook open and then hibernating my laptop and then
opening it back up. It seems that a temporary drop in communication with
Outlook Client vs. Exchange Server results in a loss of connection and thus
results in this error. As mentioned before, I have to completely kill
Outlook and re-open it to re-establish the connection and resolve.

Along these same lines, I would think that perhaps other kinds of
"disconnections" between the Outlook Client and the Exchange Server may very
well result in the varied behavior where clicking on some users provides this
erorr and others don't (perhaps if the affacted user of the shared calendar
loses his/her connection?).

It seems to me that this is a bug, whereby if the Outlook Client loses its
connection with the Exchange Server, upon reconnecting it should re-establish
the connection with the shared calendars (as opposed to returning an error
and forcing a complete shut-down/restart of the Outlook Client).

I would be curious to hear others thoughts on this as well and if they can
also see that disconnections cause this error.

"SunKing" wrote:

I am having the same problem. It is random as to whose calendar I will
receive this same error when I click on it. I have people using Outlook 2003
and 2007 and this error is not prejudiced. Close/re-open of Outlook does not
resolve. If I close Outlook and go into Task Manager, I see Outlook.exe
running and I select End Task. Upon re-opening Outlook it then works
appropriately.

I have also posted another thread specific to shared calendars not always
saving upon close/re-open of Outlook. Sometimes they are all there,
sometimes they are not, and sometimes just some of them show. I'll bet this
has something to do with this as well.

"Trumpeter" wrote:

I am running Outlook 2007 in an exchange 2003 environment. For 2 of the
shared calendars I access, most times I try to display them, I get an error
that says "The messaging interface has returned an unknown error. If the
problem persists, restart outlook." It doesn't fail 100% of the time, but it
does usually fail. I have access to 5 other calendars that work fine. I
double-checked the permissions on the 2 that work, and I have author-level
permissions. The affected calendars display properly for other users in the
office who are running outlook 2003.

I've seen the error on the knowledge base with regards to printing a shared
calendar, but not for simply displaying them, as I am trying to do. Anybody
have any insights?

Hello,

Got the same problem with Outlook 2007 on winXPsp2 PCs. After
reading Sunking post, I have set the hibernate parameter to 2 hours
and POUF! the problem goes away.

Microsoft should read this post and release a hotfix.

Yeah, the scads of information you have in your post is a roadmap for a hotfix... sigh

--�
Milly Staples [MVP - Outlook]

Post all replies to the group to keep the discussion intact. All
unsolicited mail sent to my personal account will be deleted without
reading.

After furious head scratching, Lenglo asked:

| Hello,
|
| Got the same problem with Outlook 2007 on winXPsp2 PCs. After
| reading Sunking post, I have set the hibernate parameter to 2 hours
| and POUF! the problem goes away.
|
| Microsoft should read this post and release a hotfix.

Hi Lenglo - Can you please elaborate on the location of the hibernate
parameter for me? I am unfamiliar with that config, but I certainly would
like to try this out myself.

Thread Note: This continues to happen even without hibernating in a random
fashion for me (sometimes certain shared calendars do this and others don't),
but for sure every time I hibernate it does.

Thanks in advance! -SunKing

"Lenglo" wrote:

Hello,

Got the same problem with Outlook 2007 on winXPsp2 PCs. After
reading Sunking post, I have set the hibernate parameter to 2 hours
and POUF! the problem goes away.

Microsoft should read this post and release a hotfix.