Fix “Failed to Lock the File” Error on VMWare Workstation 12

Last Updated on March 11, 2021

One of my testing/sandbox computers, that’s not running on a UPS, was unexpectedly powered off the other day when a falling tree branch in my neighborhood took out a power line. Hours later when the power was back and I turned on my computer, one of my virtual machines running on VMware Workstation 12 wouldn’t start and had an error that mentioned “Failed to Lock the File” and “Module Disk Power on Failed”.


Of course, the first thing I did was a search on google that lead to quite a few promising results.

I ended up on this VMware Community forum post and after a bit of reading I found the answer. It involves some .lck files that must be deleted, which are “Lock Files” that are created while Virtual Machines are running so that the filesystem is only edited by the controlling Virtual Machine and not outside sources. When my computer’s power was cut off unexpectedly, the Lock Files weren’t automatically deleted as they are supposed to be when a VMware VM shuts down.

How I Fixed the “Failed to Lock the File” and “Module Disk Power on Failed” Errors

First thing to do is open up the directory where your virtual machine’s files are stored. I used poorly named folders for my VMs like an asshole, so I had to look at my VM’s “Virtual Machine Details” dropdown on it’s Workstation tab to see which directory it was in.


After getting into the correct directory for my Scrapebox VM, I looked for all the folders with .lck ending and made a backup of them before deleting. The backup was just in case deleting the files didn’t fix the problem and I needed them back, you can see the backup .zip highlighted in the below screenshot.


However, thankfully my backup wasn’t needed because deleting all of the .lck files fixed my “Failed to Lock the File” and “Module Disk Power on Failed” error. My virtual machine started up without any issues with the .lck files removed!

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