In the latest case of disappearing updates, Microsoft publicly announced and released SQL Server 2014 Service Pack 1 on April 15th. If you follow our sister site SQL Server Pro, the day after release Tim Ford suggested that SQL Server folks hold off on downloading SP1 due to reported problems.
Installation problems were found with SP1 causing Microsoft to subsequently to pull the download. For those with issues after downloading SP1, there's a workaround outlined in the modified, original SQL Server 2014 SP1 announcement: SQL Server 2014 Service Pack 1 has released
So, when will SP1 be fixed? When will a fixed version be available?
Microsoft can only suggest that SP1 will be rereleased in a few weeks.
Botched updates have become such common place for the software company that many customers' systems are purposely going unprotected, delaying updating due to fear of problems. A few weeks is not long to wait if the company can get it right this time.