VMware what V4 - there are a number of VMware products (ESX\vSphere Hypervisor, VMware Server, VMware Workstation, VMware Fusion) that range in current version from V3 to V7 and the VM base formats may need some massaging to move from one base format to another.
In any case your best bet may be VMware Player V3.1 if the original source of the VM image is a Workstation\Player compatible image. Player is free BTW.
Edited to add. What you should be able to do, provided you have a spare machine that you can temporarily install ESXi on is to download and install ESXi, bring the VM up on ESXi temporarily and then use VMware Converter to carry out a conversion directly to VMware Player. If Converter isn't happy to play directly with Player then you can use a temporary VMware Workstation install that Converter definitely supports (it's built in to Workstation). You get a 30 or 60 day eval license with Workstation so you can get all the components without having to pay for licensing if this is a one off exercise.
There are third party converters that will do this too but I'm not aware of any that are free.