If you cannot migrate or power on a VM created on a newer version of ESX/ESXi to an older version, it might be due to VM hardware version support. To resolve this issues, consider downgrading your VM hardware version. There are a number of different ways to do this without having to rebuild the VM. The easiest way to consider is outlined below.
- Power the VM off, then change to Datastore Browser view after you determine on which datastore the VM’s disks reside (use the Sumarry tab).
- Open the VM’s folder and highlight the VMX file (Fig. 1-1). Download the file by clicking on the Download icon (Fig.1-2). Rename the VMX file in case you need to revert.
- Remove the VM from inventory by right-clicking on it and selecting Remove from Inventory.
DO NOT SELECT DELETE FROM DISKDo NOT select delete from disk to remove the VM from inventory.
- Edit the downloaded VMX file using something like Notepad++. Find the line with the virtualHW.version value and change it accordingly. In Figure 3, we changed the previous value of 10 to 8. This means that the hardware version has been downgraded from 10 to 8. Now, update the document according to your needs.
- Back in Datastore Browser, upload the modified VMX file by clicking on the Upload button. After uploading it, right-click on it and select Register VM. Provide the info requested by the Register Virtual Machine wizard and you’re done.
You should now be able to power the VM back on.
Other methods include using VMware Converter or creating a new VM of the correct hardware version and then attaching the existing virtual disks to that.