ZCP 7.1 migration to Kopano setSyncStatus(): collision

I would like to migrate a Zarafa mysql DB to Kopano.
After Import and restart from Kopano with this Parameter --restart-searches, I still have this Error Message:

Tue Nov  7 11:14:19 2017: [crit   ] Starting rebuild of search folders... This may take a while.
Tue Nov  7 11:14:19 2017: [crit   ]   Rebuilding searchfolders of store 695
Tue Nov  7 11:35:40 2017: [crit   ]   Rebuilding searchfolders of store 717
Tue Nov  7 11:35:52 2017: [crit   ]   Rebuilding searchfolders of store 41008
Tue Nov  7 11:35:52 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:52 2017: [crit   ]   Rebuilding searchfolders of store 41167
Tue Nov  7 11:35:52 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:52 2017: [crit   ]   Rebuilding searchfolders of store 52334
Tue Nov  7 11:35:52 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:52 2017: [crit   ]   Rebuilding searchfolders of store 202545
Tue Nov  7 11:35:52 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:52 2017: [crit   ]   Rebuilding searchfolders of store 219577
Tue Nov  7 11:35:53 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:53 2017: [crit   ]   Rebuilding searchfolders of store 221885
Tue Nov  7 11:35:55 2017: [crit   ]   Rebuilding searchfolders of store 292091
Tue Nov  7 11:35:55 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:55 2017: [crit   ]   Rebuilding searchfolders of store 305266
Tue Nov  7 11:35:55 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:55 2017: [crit   ]   Rebuilding searchfolders of store 324415
Tue Nov  7 11:35:55 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:55 2017: [crit   ]   Rebuilding searchfolders of store 353507
Tue Nov  7 11:35:55 2017: [crit   ] ECSearchFolders::Search() CreateSessionInternal failed: 0x80000002
Tue Nov  7 11:35:55 2017: [crit   ]   Rebuilding searchfolders of store 362093
Tue Nov  7 11:35:57 2017: [crit   ]   Rebuilding searchfolders of store 413092
Tue Nov  7 11:35:58 2017: [error  ] setSyncStatus(): collision

I think I have solved the Problem.

1.) Stop all kopano services
2.) Import the mysql zarafa.dump
3.) Remove all files from /var/lib/kopano/search/
4.) Start all services from kopano
5.) Wait until the new index files are done

Now, I have no Error setSyncStatus(): collision