When performing a replication job you see the following error "Error Message: 2721 - /root/vzva/201112271051/ssh: /root/vzva/201112271051/vddk-5.0/lobcrypto.so.0.9.8: no version information available (required by /root/vzva/201112271051/ssh)"
When the replication job was originally setup you had the same version of ESX(i) at the source and at the target. You setup replication jobs and VMs replicated without an issue. Since you have upgraded your source hosts to a newer version of ESX(i) while your target hosts are now running an older version or ESX(i). Along with the error you may see the following error as well "FATAL repl_wrong_size target vix:r:XXX.XXX.XXX:902[target datastore] differentVM_Replica/differentVM_Replica.vmdk:moref=vm-64049:snapshot-68026:3 has the wrong size [at send_hashes_thread:504]
FATAL internal internal error [at pkt_recv_unlock:82]"
Based on this additional error the replica VM that is being used for this replication job is a different VM than is supposed to be used.
You will need to edit your replication job to make sure the correct target host is being used and the correct replica VM is chosen as the preseed VM. If your source hosts are newer than your target hosts this may not be possible because vRanger will not allow you to select a target host that is running an older version of ESX(i) than your source hosts and you will have to upgrade your target hosts to the same version of ESX(i) as your source hosts. Once that is done you will be able to edit the replication job selecting the correct target host and the correct replica VM as the preseed VM.