I recently had a patching issue with SQL Server 2014 SP3. When I tried installing the SP3 update it kept failing with error code 0x858C001E. It turns out that this can be caused if the program files directories for SQL Server are compressed.  The folder paths to check are listed below as documented here: https://wiert.me/2017/03/16/fixing-0x858c001e-error-on-sql-server-20122014-updates/ 

For x86 systems, ensure these directories are not compressed:

  • C:\Program Files\Microsoft SQL Server
  • C:\Program Files\Microsoft SQL Server Compact Edition

For x64 systems, ensure these directories are not compressed:

  • C:\Program Files\Microsoft SQL Server
  • C:\Program Files x86\Microsoft SQL Server
  • C:\Program Files x86\Microsoft SQL Server Compact Edition

I found that some of the directories were compressed due to the customer trying to free up disk space on the system drive.  After uncompressing the Microsoft SQL Server folders, the update installed, and the server needed a reboot to complete.