Skype for business FrontEnd and NetApps fileshare - error 32008

Log Name:      Lync Server
Source:        LS Storage Service
Date:          23/02/2016 10:33:34
Event ID:      32008
Task Category: (4006)
Level:         Error
Keywords:      Classic
User:          N/A
Computer:      xxx
Description:
Unexpected exception.

Message=Error: Path \\yyy.domain.com\SFBSHARE\1-WebServices-12\StorageService failed to be read for flushed data. Error details: System.IO.IOException: Invalid Signature.

   at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileSystemEnumerableIterator`1.CommonInit()
   at System.IO.FileSystemEnumerableIterator`1..ctor(String path, String originalUserPath, String searchPattern, SearchOption searchOption, SearchResultHandler`1 resultHandler, Boolean checkHost)
   at System.IO.Directory.GetFiles(String path, String searchPattern, SearchOption searchOption)
   at Microsoft.Rtc.Internal.Storage.Sql.LyssDal.CheckFilePathForFlushedFiles(StoreContext ctx, String parentFilePath, Boolean checkArchived, Boolean& errorOccurred, Int32& numDataFilesToReport)

Exception: Invalid Signature.

Stack Trace:    at System.IO.__Error.WinIOError(Int32 errorCode, String maybeFullPath)
   at System.IO.FileSystemEnumerableIterator`1.CommonInit()
   at System.IO.FileSystemEnumerableIterator`1..ctor(String path, String originalUserPath, String searchPattern, SearchOption searchOption, SearchResultHandler`1 resultHandler, Boolean checkHost)
   at System.IO.Directory.GetFiles(String path, String searchPattern, SearchOption searchOption)
   at Microsoft.Rtc.Internal.Storage.Sql.LyssDal.CheckFilePathForFlushedFiles(StoreContext ctx, String parentFilePath, Boolean checkArchived, Boolean& errorOccurred, Int32& numDataFilesToReport)
Cause: Unexpected exception.
Resolution:
If problem persists, notify your organization's support team with the event detail.


Strangely enough this error appears only on one frontend out of three.  As if other frontends are configured differently.

The only idea for the moment is to reboot server.

There are some resources in internet pointing to SMB issue with secure negotiations:
http://www.thomasmaurer.ch/2013/03/windows-8-or-windows-server-2012-cannot-access-netapp-smbcifs-share/
https://support.microsoft.com/en-us/kb/2686098

From this frontend we can do netbios dir
dir \\yyy\SfBShare  but FQDN
dir \\yyy.domain.com\SfBShare gives
"Invalid Signature."

net use gives

"System error 2148073478 has occurred."


Indeed reboot solved the issue.