Ubuntu users are reporting that when they try to unzip a file using the Ubuntu software Unrar, they are getting a Fix Password required Error. The error message says that the user needs to enter a password to access the file. However, there is no way for the user to enter a password. This problem seems to be affecting Ubuntu 14.04 and 16.04 LTS versions of the operating system. It is not clear how widespread the problem is or what might be causing it. If you are experiencing this problem, you can try one of the following solutions:

  1. Try installing an older version of Unrar: Ubuntu users can try installing Unrar version 3.x or 4.x instead of the current version 5.x. These older versions may work without requiring a password.
  2. Change your login password: If you have already changed your login password, you can try resetting it by entering this command into a terminal window: sudo passwd . This will reset your login password and allow you to unzip files without having to enter a password first. ..

It turns out that this error message pops up for one of two other reasons:

The files are named incorrectly or a file is missing. Remember that Linux is case-sensitive and all files in the set should be named similarly. One of the files is damaged and might need to be repaired using GPar2, if you have the matching PAR files.

Here’s the irritating error message.

If you’ve also got the corresponding PAR recovery set files, what you’ll want to do is install GPar2 using the Add/Remove Applications, or by just typing the following command into a terminal prompt:

Then you can just open up any one of the .par2 files and click the Repair button, which will take a fairly long time to complete, but should allow you to extract without errors.

More information on PAR or Parchive files can be found at Wikipedia, of course:

http://en.wikipedia.org/wiki/Parchive