======Offline Archive Error Messages======
  * (2) ZIP file structure invalid (eg disk corruption)
  * (3) Out of memory
  * (4) Internal logic error in ZIP compressor
  * (8) ZIP file invalid or insufficient memory
  * (10) Temporary File failure
  * (11) Input file read failure (eg virus scanner blocking access to archived files)
  * (12) Nothing to do
  * (13) Missing or empty ZIP file
  * (14) Output file write failure, possible disk full (or disk error)
  * (15) Could not create output file (eg bad ZIP filename or location)
  * (18) File not found or no read permission