I have been advised that there are some issue for downgrading VMs from VMware workstation 11 to 10. I was finally able to reopen converted VMs in v10. The compatibility wizard didn't work, but i was able to export them to OVF (open format) and then re-import them into version 10. That worked, but not sure if i should be expecting some issues in the future.I did get an error that "OVF didn't pass specification conformance or virtual hardware compliance". I clicked Retry for that error and then import was successful. Please let me know what are some known issues with downgrading from v11 to 10 and if It would be wise to still purchase the upgrade license for VMWare 11. Because if we will be getting more issues, then getting the license for only $149 sounds like a better choice.