Hi,
It sounds like your OVA file might be corrupted. Can you do an MD5 check and make sure your downloaded vmware-io-analyzer-1.5.1.zip has an MD5 checksum of "2a21a36f034389bc96f42ee3ff7608c4"? Also, The zip file should be of size 1,214,902,904 bytes.
We do not maintain previous release so it is not recommended to use 1.5.0 version.
Thanks,
Chien-Chia