[SOLVED] Exchange 2019 / Outlook Unknown Error when forwarding meeting

Question

Hello,

Users are all unable to forward meetings. It does not matter if they're reoccuring or single meetings. Does not matter if they're the senders or not. Same issue persists when running Outlook in safe mode.

We've tried redoing the mail profile in Control Panel.

Outlook does not provide any details, it just prompts "Unknown Error" ("Okänt fel" Swedish) when pressing send.

Our Exchange Server is running Exchange 2019 latest CU.

Users are running the latest Outlook client. For example, mine is Version 2105 (version 14026.20246 click-and-run)

The remote domain of the server is configured the following:

[PS] C:\Windows\system32>Get-RemoteDomain | fl  
  
  
RunspaceId                           : 8c1ffdd8-5e00-4288-bcd3-bb141830fdf3  
DomainName                           : *  
IsInternal                           : False  
TargetDeliveryDomain                 : False  
ByteEncoderTypeFor7BitCharsets       : Undefined  
CharacterSet                         : iso-8859-1  
NonMimeCharacterSet                  : iso-8859-1  
AllowedOOFType                       : ExternalLegacy  
AutoReplyEnabled                     : True  
AutoForwardEnabled                   : True  
DeliveryReportEnabled                : True  
NDREnabled                           : True  
MeetingForwardNotificationEnabled    : True  
ContentType                          : MimeHtmlText  
DisplaySenderName                    : True  
PreferredInternetCodePageForShiftJis : Undefined  
RequiredCharsetCoverage              :  
TNEFEnabled                          :  
LineWrapSize                         : Unlimited  
TrustedMailOutboundEnabled           : False  
TrustedMailInboundEnabled            : False  
UseSimpleDisplayName                 : False  
NDRDiagnosticInfoEnabled             : True  
MessageCountThreshold                : 2147483647  
AdminDisplayName                     :  
ExchangeVersion                      : 0.1 (8.0.535.0)  
Name                                 : Default  
DistinguishedName                    : CN=Default,CN=Internet Message Formats,CN=Global Settings,CN=CONTOSO,CN=Microsoft Exchange,CN=Services,CN=  
                                       Configuration,DC=CONTOSO,DC=INTERNAL  
Identity                             : Default  
Guid                                 : 29d09ddb-c02d-43ad-add2-827651f0f9ed  
ObjectCategory                       : CONTOSO.INTERNAL/Configuration/Schema/ms-Exch-Domain-Content-Config  
ObjectClass                          : {top, msExchDomainContentConfig}  
WhenChanged                          : 2021-06-11 09:02:19  
WhenCreated                          : 2005-11-18 09:25:12  
WhenChangedUTC                       : 2021-06-11 07:02:19  
WhenCreatedUTC                       : 2005-11-18 08:25:12  
OrganizationId                       :  
Id                                   : Default  
OriginatingServer                    : NF-ADSRV01.Contoso.internal  
IsValid                              : True  
ObjectState                          : Unchanged  

Any assistance in troubleshooting or at least getting something more detailed than "Unknown error" is most welcome.

Answer 1

Just got an update to my Outlook/Office, without running inside build.

New Build number: Version 2105 ( Version 14026.20308 )

Forwarding meeting now works!

I can also confirm that this issue is solved: https://support.microsoft.com/en-us/office/-the-properties-of-the-message-have-been-changed-prompt-when-forwarding-replying-in-outlook-c42f5eec-382e-4521-bee4-72f7625460db?ui=en-US&rs=en-US&ad=US

So I assume they were tied together @Kael Yao-MSFT

@Les Papp
@John Duplay
@Chris Glabu
@Frenzel, Christian
@Cleeren Bart
@Hof, Sabine

Ask users to update office or trigger an update via GPO / PS and you should be good.

I've confirmed with multiple workstations in my environment that it works.

Answer 2

Hello,
same problem here, creating new profile didn´t help, we´re using o365 with actual build (2105) on Exchange Server 2016 CU19

Solutions are current only go back to Realease Version 2101 (Build 13628.20448) (Problem exist since March Update 2102) or enable cached mode.
Please fix it

Answer 3

Hi,

I have the same issue as EmilGustafsson.
We are running Exchange 2016 and Outlook365 2102 (13801.20266)

Forwarding of meetings results in "unknown error"

@Emil Gustafsson
Are you using F-Secure Anti Virus?

Regards
Peter

Answer 4

The post below stated to re-create your profile, and I tested it, and it works

https://community.spiceworks.com/topic/2320082-outlook-365-unable-to-forward-meeting-invites-unknown-error

Answer 5

Same Problem here.
Re-creating profiles for >500 User - not a good Idea.

It really sucks - Updates clearly aren't tested well enough because many times everything works awful after update.