Upgrade from 6.15.2 to 7.2.2 fails

[Ed Kok]

When running the atlassian-confluence-7.2.2-x64.bin from /tmp the installer fails with:

The upgrade process will shut down your existing Confluence installation to complete the upgrade.

Do you want to proceed?
Upgrade [u, Enter], Exit [e]
u

Your instance of Confluence is currently being upgraded.
Shutting down Confluence...
Checking if Confluence has been shutdown...
Backing up the Confluence installation directory

Deleting the previous Confluence installation directory...

Extracting files ...
confluence/WEB-INF/atlassian-bundled-plugins/document-conversion-library-
The installation file is corrupted. If it is a download please try it again.
Rolling back changes ...

Also a fresh downloaded copy fails with the same error.
The server is a RedHat rhel7 64-bit with plenty of diskspace and memory.

Suggestions welcome.

[Ed Kok]

I'm lucky it is on a VM of which I made a snapshot before the upgrade because the install directory was completely removed. Somuch for "Rolling back changes ...".