A big map extent is set for the cached scale, causing the size of the cache file to be big.
Problematic or corrupted bundle files exist in the cache folder.
An existing cache is updated after upgrading ArcGIS.
Solution or Workaround
Use one of the following solutions according to the causes stated above to solve this problem:
Disable the Windows DFSR, and configure the ArcGIS for Server cache directory to not use the Windows Distributed File System (DFS) namespace system. For more information about configuring the ArcGIS cache directory, refer to the following web help document, ArcGIS for Server: Local cache directories on the server.
Monitor the cache completion status. For more information about monitoring cache completion status, refer to the following web help document, ArcGIS for Server: Viewing cache completion status. Search for the problematic file, access the cache folder through Windows Explorer, and delete the problematic files.