Can't increase virtual disk size due to non-existent snapshots

I need to increase my virtual disk size in order to install Windows 10 upgrade. Even though I have deleted all the snapshots, I receive a message that I have to delete snapshots before I can increase disk size.

I have found this supposed "help" article - http://kb.parallels.com/en/118415 - but this is utter gobbledygook. Please can you explain how to resolve this issue in normal simple steps.

 

Hi @rtom157 , I suggest you to take a backup of your Virtual Machine and then execute the terminal command to merge snapshots as given in this article
Once this is done try to increase virtual hard disk size again and check how it goes.