I have windows 10 host and virtual mint Linux as a guest. I had a situation like I need more space for the guest os. But my host didn't have enough space so that I can't resize the vm os from the host. So I transferred the vm to another windows 10 laptop with sufficient free space copied the complete directory "C:\Users\Soma\VirtualBox VMs\eric_mint19". Then resized the vdi file. Resize was successful. To make sure I made new vm with the resized vdi file. It was working fine.
Finally, I transfer only the vdi file to original windows 10. There I couldn't make new vm by the resized vdi. The step I did is as. I made new vm and selected existing vdi file. And save it. Then tried to start the vm. I doesn't boot up. Instead it shows ubuntu busybox terminal. I don't know how to boot up now. Please let me what can I do?