I could not drop that index, ..

TITLE: Microsoft SQL Server Management Studio

------------------------------

Drop failed for Index 'IX_OperatingLimitHighValues_EffectiveTime'. (Microsoft.SqlServer.Smo)

For help, click: http://go.microsoft.com/fwlink?ProdName=Microsoft+SQL+Server&ProdVer=10.50.4000.0+((KJ_PCU_Main).120628-0827+)&EvtSrc=Microsoft.SqlServer.Management.Smo.ExceptionTemplates.FailedOperationExceptionText&EvtID=Drop+Index&LinkId=20476

------------------------------

ADDITIONAL INFORMATION:

An exception occurred while executing a Transact-SQL statement or batch. (Microsoft.SqlServer.ConnectionInfo)

------------------------------

Lock request time out period exceeded. (Microsoft SQL Server, Error: 1222)