Hello
the relevant error (from helper's log) is:
--> /bin/tar_1.20: Archive value 9671017472 is out of size_t range 0..4294967295
I remember this has occasionally happened before but unfortunately I don't remember what the workaround was (which may mean there is not a standard one).
The guess now is first to check the version of 'tar' on the source machine and eventually try with another one. The one Converter uses for untaring is 1.20.
You can also eventually copy the same binary from converter helper VM, the file is "/bin/tar_1.20". However logging in helper requires some hacking effort. If you can't manage, I'll explain how to do it.
HTH
Plamen