If you are conversant with WDS, MDT and Windows Image manipulation, you must have come across this error multiple times. There are a lot of DISM error 87 and there isn’t any single solution for all. It makes sense to analyse the specific error promoted and then, have it resolved. In this article, you will learn how to fix “DISM Error 87: The package is unknown”. Please see how to Fix “Unknown hard error” on Windows Server and Windows 10, and Nslookup unknown: Fix cannot find non-existent domain.

Here are some related errors you will come across when modifying Windows Image. How to fix error 0xc1510114: The wim file needs to be remounted, error 0x80070002: When trying to mount an image file, error code 15601: How to resolve DISM unspecified error when removing preinstalled packages, error 0xc1420127: The specified image in the specified wim is already mounted for read and write access, and Error 740: Elevated permissions are required to run DISM.

Reason for the DISM Error 87 Error

As you can see from the output below, I had a error prompt because I misspelt the switch “remove-appxprovisionedpackage. See this article on how to remove built-in application from Windows Image.

The solution to fixing the Package is unknown

After entering the correct command as shown below, I was able to remove the pre-installed application.

dism /image:G:\Path-to-the-mount-file\MountZ /Remove-Provisionedappxpackage /PackageName:Microsoft.WindowsCalculator_2015.1009.20.0_neutral_~_8wekyb3d8bbwe

You can also get the error 87 when you do not execute DISM with Administrator privilege.

Please just take a look at the output for reasons for the error prompt. “Make sure that the cmd window title is: Administrator: Command Prompt”. Please see How to fix Unknown Hard Error on Windows Server and Windows 10, and how to fix Error 183: The specified image is currently being serviced

I hope you found this blog post helpful on how to fix DISM Error 87: The package is unknown. If you have any questions, please let me know in the comment session.