Hello!

My BES stops syncing since the last two weeks suddenly.

When I look in BAS under manage users, I can see that some users "last contact date" is up to date, but I also see that many other users "last contact date" is NOT up to date.
I solved this problem by restarting the BB controller service (but all services are started and running), after 5mins of waiting all devices "last contact date" are up to date and the users receive messsages on their devices again.

The windows application logfiles showing that he could not start the mailbox from the effected users.

In which BB log files I should find some error about this to get this problem fixed?

Have a look at the MAGT log for error messages.

On the day where BES stopped syncing I´ve 3 MAGT log files.
At the first logfile I found at the bottom of the logfile following:

"[30173] (07/01 00:50:38.285):{0x4278} BlackBerry server terminated as it failed to shutdown in 40 seconds
====== END OF LOG ======"

The other two logfiles are so big, I´ve no clue where to start for these twos...

Just search for the error you found in the Application log. Example: In the MAGT log, search for "not started" and any messages just before that.

I see alot of "CalICSSynchronizer::Initialize - OpenProperty failed: (0x80004002)" erros for every user account in the windows application log
and also "CalICSAgent::Start Could not Initialize Synchronizer for "

But I cannot find the route cause...

Please use the IEMSTest tool to see if BES can make a proper connection to the affected users. Details can be found here:

KB31053-How to run the IEMS Test

Thank you for the link, but I can access all mailboxes with my BES Admin account.

The errors which I have posted is a result of an other error which accours befor it, but I can´t find it in the logfiles....

But this indicates that BES can't access some users properly and that's why I suggested the IEMSTest tool.

Once I restarted the BES controller service, I´m able to open the mailboxes.
But when BES stopps syncing I can find the following in the MAGT log file:

Retry start for user: user@test@domain.com
Starting handheld for user@test@domain.com

MAPIMailbox::MAPIMailbox ServerDN=/o=webmail.domain.com/ou=First Administrative Group/cn=Configuration/cn=Servers/cn=webmail.domain.com/cn=Microsoft Private MDB, MailboxDN=user@test@domain.com

{user@test@domain.com} MAPIMailbox::MAPIMailbox - OpenMsgStore (0x8004011d) failed, MailboxDN=user@test@domain.com, ServerDN=/o=webmail.domain.com/ou=First Administrative Group/cn=Configuration/cn=Servers/cn=webmail.domain.com/cn=Microsoft Private MDB

MAPI call failed. Error 'N/A', LowLevelError 0, Component 'Personal Folders', Context 269287681

User user@test@domain.com not started

OK, please look at this KB and let me know if it solved the problem:

KB20608-Random BlackBerry smartphones fail to start and "MAPIMailbox - OpenMsgStore (0x8004011d) failed" appears in BlackBerry Messaging Agent and Application logs due to Microsoft Exchange 2010 Throttling Policy

Thanks for you reply!
I also found some interessting Application errors in the event viewer:

Error BlackBerry Router Event ID 10000
[SERVICE_RELAY_SESSION:S34164325:0x0064EA28] Service transaction not found. SERVICESESSION_TAG=4507046

I think this error happens before when BES stops syncing...

Yes, but could still be the issue mentioned in the article above. Please go through the steps in the article and see if that solves your problem.