How can I fix this issue? delete the vNetwork Adapter to add it back?
Workaround : Make sure you have VM hardware version 10 and choose OS type to ‘Other 3.x or later Linux (64-bit) and then retry.
The VM was installed on the ESXi 5.5 previously. Once, I migrated the VM from ESXi 5.5 to ESXi 6.5, then taht changed as VM version 10??
You have to do it manually,
Shut down the VM, right-click the virtual machine and select the menu option to upgrade virtual hardware:
In the vSphere Client, the option is Upgrade Virtual Hardware.
In the vSphere Web Client, the option is Compatibility > Upgrade VM Compatibility.
If I migrate the VM from the version 8 of ESXi 5.5 to ESXi 6.5 as keeping the same of source, that will change as version 10???
No, hardware is changed with esxi edition. When you migrate a VM from a lower version of esxi to upper one, hardware version is upgradable but you will have to upgrade it manuall. This will give you enhanced hardware capabilities like USB 3.0, number of vmdks you can attached to VM, type of network adapters etc.
