No Access to Archive Explorer in Outlook

Hello, 

we are facing an issue on customer side. Customer uses EV 9.0.4 and a combination of Outlook add-In  9.0.4.1125 and 10.0.4.1354 in an citrix environment. It shines that Outlook users with Add-In 10.0.4.1354 are unable to open Search/ArchiveExplorer in Outlook. The Desktop Setting "Launch Archive Explorer" is set to "In Outlook". When Clicking the ArchiveExplorer/Search button it displays the information in the attached screenshot. Manual Archiving /Retrieval is working and direct access to AE/Search with Internet Explorer also works. 

Clienttrace shows the following information:

15/04/2015 11:30:36.979[39376][L]: ActionWebCommon<0>::LaunchURLInOutlook: 0x0
15/04/2015 11:30:36.979[39376][M]: Launching EV web application in Outlook: http://<evserver>.domain.de/EnterpriseVault/archiveexplorerui.asp?server=Exchange&mbx=SMTP:user.user@domain.de&outlook=12

following

15/04/2015 11:30:36.994[39376][L]: ~LaunchURLUsingWebControl::GoToURL: 0x80004005
15/04/2015 11:30:36.994[39376][L]: ~ActionWebCommon<0>::LaunchURLInOutlook: 0x0
15/04/2015 11:30:36.995[39376][L]: ~ActionWebArchiveExplorer<class ECETraits>::OnAction: 0x0
15/04/2015 11:30:36.995[39376][L]: ~Action<class ActionWebArchiveExplorer<class ECETraits>,class ECETraits,1>::operator ()
15/04/2015 11:30:36.996[39376][L]: ~CCommands::DoArchiveExplorer: 0x0
15/04/2015 11:30:36.996[39376][H]: A COM error exception has been caught: 80004005
15/04/2015 11:30:36.996[39376][L]: ~CCommands::DoCommand: 0x80004005

I've taken a look at https://www-secure.symantec.com/connect/forums/ev-1004-outlook-add-unable-view-anything-search-vaults-or-ae where RichardG says 

"The EV add-in now uses a hidden folder and sets the home page URL on that folder to point at the appropriate EV web app."

But the solution mentioned here does not solve this issue. 

Customer also checked the steps from

http://www.symantec.com/docs/TECH223437 and

http://www.symantec.com/docs/TECH194935 without success.

Has anyone seen this before?