SEP client repeatedly fails to download specific definitions from the SEPM. Client system log contains errors that indicate that Liveupdate is unable to process the suspect definitions.

SEP Client:
System Log-
"A content update package from the management server failed to unzip.  The update will be reattempted."
"New content update failed to download from the management server." 
"Remote file path: ...\\:8014/content/{5A7367E1-D1F6-43b5-BD94-4AFFA896D724}/151028036/Full.zip""

SEPM 
iDeltaThreadPool_1-0 log-
SEVERE: IncDelta error: IncrementalDeltaResult [deltaFilePath=F:\Program Files (x86)\Symantec\Symantec Endpoint Protection Manager\Inetpub\content\{5A7367E1-D1F6-43b5-BD94-4AFFA896D724}\151028036\xdelta151028036_To_161121023.dax, deltaFileName=xdelta151028036_To_161121023.dax,
 request=IncDeltaRequest @-483862330 iFWDdelta: 151028036->161121023 [incZipOutputPath=...\content\{5A7367E1-D1F6-43b5-BD94-4AFFA896D724}\151028036\xdelta151028036_To_161121023.dax, isOutputAvailable=false, destFullPath=C:\ProgramData\Symantec\Definitions\SymcData\spcPorscheSMRDef\20161121.023, srcFullPath=...\content\{5A7367E1-D1F6-43b5-BD94-4AFFA896D724}\151028036\Full, isForwardDelta=true, tempSrcFullDirPath=...\content\{5A7367E1-D1F6-43b5-BD94-4AFFA896D724}\151028036\Full, tempDstFullDirPath=C:\ProgramData\Symantec\Definitions\SymcData\spcPorscheSMRDef\20161121.023],
 result=-533463040, ex=com.sygate.scm.server.util.ServerException: Unexpected server error.]

Check of the full.zip files indicated in the errors show they are not the correct size.

Corrupted full.zip file exists in database and in \Program Files (x86)\Symantec\Symantec Endpoint Protection Manager\Inetpub\content folder.
The file/s may exist in several monikers.
The existance of the corrupted files prevents Liveupdate from replacing the files.

Review SEPM logs for Delta creation errors to obtain monikers to check for corruption.
Open a case with Symantec Support to obtain ContentCleanupTool to remove the corrupt definitions from database and SEPM content folders.
Run SEPM Liveupdate to download updated definitions.