Dear Padmanabha,

Hope you are doing well

Method 1 :

From virtualbox create a new virtual machine (important: if machine exported was 32bits, new machine should be 32bits, and if exported was 64bits then new machine should be 64bits). Finally attach the existing vmdk file instead of creating a new one and that's all. Then boot up the newly created virtual machine and it will work fine.

Metrhod 2 :

Please go into the folder "C:\Users\COMPUTER_NAME\.VirtualBox\Machines\VM_NAME\" and generally there are two xml files but for some reason they both had suffixes.

1. VM_NAME.xml-prev
2. VM_NAME.xml-tmp

So it simply just couldn't find "VM_NAME.xml" because it technically didn't exist.
Just make a copy of the "VM_NAME.xml-prev" file and renamed the copy to "VM_NAME.xml"

Restart VirtualBox and it will work fine.

Please let me know if you have any further query regarding this.

Feel free to contact us in case you have any query. 
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