Invalid URI: The hostname could not be Parsed

Hi All,

Over the weekend I updated our Exchange 2010 environment to SP3 then updated it to Roll up 2 (all servers are now  14.03.0158.001).

The setup consists on two HT/CAS servers and two Mailbox servers.

We use linked mailboxes for all our users who are based in a separate domains and while trying to grant send as permissions today:

Add-ADPermission "CN=Boss Man,U=Users,OU=Linked Mailboxes,OU=Exchange Users,OU=Users,OU=City1,OU=Sites,DC=Company,DC=corp,DC=local' " -User "system\User123" -Extendedrights "Send As"

this error appeared:

VERBOSE: [10:54:03.205 GMT] Add-ADPermission : Active Directory session settings for 'Add-ADPermission' are: View
Entire Forest: 'False', Default Scope: 'Site1.corp.local', Configuration Domain Controller:
'DC1-svrdc01.Site1.corp.local', Preferred Global Catalog: 'DC1-svrrdc01.corp.local', Preferred Domain
Controllers: '{ DC1-svrrdc01.corp.local }'
VERBOSE: [10:54:03.220 GMT] Add-ADPermission : Runspace context: Executing user: Site1.corp.local/Domain
Management/Admin Accounts/- Admin Account, Executing user organization: , Current organization: ,
RBAC-enabled: Enabled.
VERBOSE: [10:54:03.220 GMT] Add-ADPermission : Beginning processing &
VERBOSE: [10:54:03.220 GMT] Add-ADPermission : Instantiating handler with index 0 for cmdlet extension agent "Admin
Audit Log Agent".
VERBOSE: [10:54:03.236 GMT] Add-ADPermission : Current ScopeSet is: { Recipient Read Scope: {{, }}, Recipient Write
Scopes: {{, }}, Configuration Read Scope: {{, }}, Configuration Write Scope(s): {{, }, }, Exclusive Recipient Scope(s):
 {}, Exclusive Configuration Scope(s): {} }
VERBOSE: [10:54:03.236 GMT] Add-ADPermission : Searching objects "Site1.corp.local' /Sites/City1/Users/Exchange
 Users/Linked Mailboxes/Users/Boss Man" of type "ADRawEntry" under the root "Site1.corp.local'
/Sites/City1/Users/Exchange Users/Linked Mailboxes/Users/".
VERBOSE: [10:54:03.236 GMT] Add-ADPermission : Previous operation run on global catalog server
'DC1-svrdc01.Site1.corp.local'.
WARNING: An unexpected error has occurred and a Watson dump is being generated: Invalid URI: The hostname could not be
parsed.
VERBOSE: [10:54:03.392 GMT] Add-ADPermission : Admin Audit Log: Entered Handler:OnComplete.
Invalid URI: The hostname could not be parsed.+ CategoryInfo          : NotSpecified: (:) [Add-ADPermission], UriFormatException+ FullyQualifiedErrorId : System.UriFormatException,Microsoft.Exchange.Management.RecipientTasks.AddADPermission

Does anyone have any clues on where I can start with this?

Thanks