Windows server backup fails with these symptoms: In the Windows Server Backup GUI, when you double-click a failed backup: "Failed. The system writer is not found in the backup." After running "vssadmin list writers", System Writer is not listed and these two errors appear in the Application event log: -------------------------------------------------------------------------------- Event ID 8193 Volume Shadow Copy Service error: Unexpected error calling routine XML document is too long. hr = 0x80070018, The program issued a command but the command length is incorrect. Operation: Writer Exposing its Metadata Context: Execution Context: Requestor Writer Instance ID: {6B443A2A-3ABF-4DF7-87B3-C13B120D0DD2} Writer Class Id: {E8132975-6F93-4464-A53E-1050253AE220} Writer Name: System Writer -------------------------------------------------------------------------------- Event ID 8193 Volume Shadow Copy Service error: Unexpected error calling routine CreateVssExamineWriterMetadata. hr = 0x80042302, A Volume Shadow Copy Service component encountered an unexpected error. Check the Application event log for more information. Operation: Writer Exposing its Metadata Context: Execution Context: Requestor Writer Instance ID: {6B443A2A-3ABF-4DF7-87B3-C13B120D0DD2} Writer Class Id: {E8132975-6F93-4464-A53E-1050253AE220} Writer Name: System Writer -------------------------------------------------------------------------------- Fix: Various parts of Windows Server still limit path depth and number of subdirectories per directory. The temporary dirs in this location exceed those limits for the VSS writer: C:\Windows\Microsoft.Net Find out which subdirs in this structure are big. Then, stop IIS, move the contents of those temp dirs (specifically, move the 'root' subdir out of "Temporary ASP.NET Files"), then start IIS again and verify that web apps still run. If web apps still run, it is OK to delete the moved 'root' folder. see also: https://support.microsoft.com/en-us/kb/2807849 http://blogs.msdn.com/b/ntdebugging/archive/2013/08/27/missing-system-writer-case-explained.aspx note: this failure mode has similar symptoms, but is not the same cause as the above: https://support.microsoft.com/en-us/kb/2009272