[root@vps1 AMP]# ./ampinstmgr -p
[Info] AMP Instance Manager v1.3.4.0
[Notice] Running as root, instances will be created using their own users.
[Info] Upgrading instance MCMA
[Error] Failed to unpack AMP.
[Error] An exception occurred during a WebClient request.
[Info] Upgrade complete.
[root@vps1 AMP]# ./ampinstmgr -p
[Info] AMP Instance Manager v1.3.4.0
[Notice] Running as root, instances will be created using their own users.
[Info] Upgrading instance MCMA
[Debug] Running command line: "unzip -qq -o "/home/root/.ampdata/instances/AMPCache-1340.zip"" from "/home/root/.ampdata/instances/MCMA"
[/home/root/.ampdata/instances/AMPCache-1340.zip]
  End-of-central-directory signature not found.  Either this file is not
  a zipfile, or it constitutes one disk of a multi-part archive.  In the
  latter case the central directory and zipfile comment will be found on
  the last disk(s) of this archive.
unzip:  cannot find zipfile directory in one of /home/root/.ampdata/instances/AMPCache-1340.zip or
        /home/root/.ampdata/instances/AMPCache-1340.zip.zip, and cannot find /home/root/.ampdata/instances/AMPCache-1340.zip.ZIP, period.
[Info] Upgrade complete.