Her first attempt was the safe route. She used vmkfstools from the ESXi command line:
She groaned, pulled on a hoodie, and logged into the vSphere cluster from her laptop. The virtual machine in question—a critical finance app server—was frozen. The error was ugly: “Metadata file is corrupt. Cannot open disk.” fix corrupt vmdk file
If you see a .flat.vmdk (the actual data) but are missing the smaller .vmdk (the text descriptor), the VM will not boot. You must recreate the descriptor. Her first attempt was the safe route