Microsoft Windows 7

7z – “unknown method” or “unknown compression method”

This post containse the steps to fix the error messages “unknown method” or “unknown compression method” with 7 Zip

Solution to the errors: “unknown method” or “unknown compression method” with 7 Zip.

When you try to extract a .7z (7-Zip) file show the following errors:

unknown method


unknown compression method


Download and install the latest version of the 7-Zip software from

7 zip to solve unknown compression method error

Did my solution solve your problem? Leave a reply.

42 replies on “7z – “unknown method” or “unknown compression method””

Thank you thank you thank you!!! Spent the whole day searching for how to fix my problem! Really helped a lot!!!

Thank you for yout comment. Next time that you’ll receive an error, I suggest you to copy the error message directly from the error windows (Ctrl+C) and search on Google. The idea of my website is offer a solution to an error message.

i was thinking that 7-zip will work.. luckily found this and it did work.. thanks 😀

Here I thought I was having a problem of corrupt files and just needed to update the software.
Of course it seems so simple now that you told us.
Big thanks.

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