[Solved]Incompatible archive PCLZIP_ERR_BAD_FORMAT (-10) : Invalid archive structure

With the release of wordpress 2.8 there was an error while installing some plugins on the wordpress from admin panel. This error was not fixed till wp 2.8.1

When the admin tries to install the plugi, it gives the following error:

Installing Plugin: —————–

Downloading install package from http://———————-.com

Unpacking the package.

Incompatible archive PCLZIP_ERR_BAD_FORMAT (-10) : Invalid archive structure

The error can be solved by downloading this new http.php file from official WordPress site and over writing it on your current file (make sure to backup your current http.php file).


Hope it solves the issue.

Please note, if you have recently upgraded your wordpress and are getting this issue (if you have solved it last time) make sure that you have replaced the http.php file in your wordpress with the above file again.

Update: Stacy commented:

Hey guys, I found out that this error is also caused by a full directory in cpanel. Make sure you have enough disk space :) good luck !

Hopefully this will solve the issue with wordpress sayingIncompatible archive pclzip_err_bad_format (-10) : Invalid archive structure

41 comments on “[Solved]Incompatible archive PCLZIP_ERR_BAD_FORMAT (-10) : Invalid archive structure

  1. It didn’t work for me unfortunately. I still get
    Incompatible archive PCLZIP_ERR_BAD_FORMAT (-10) : Unable to find End of Central Dir Record signature

  2. hopefully it should (didn’t try myself though) you can try it and confirm it to us too.

    please make sure that you make the backup of your current file before replacing it.

  3. I’m getting the same error when trying to update plugins and reinstall wordpress, but I’m using wordpress 2.9, and the http.php file replacement didn’t work for me.

    1. a quick test could be to install a new wordpress 2.9 in a new directory/subdirectory on your same server and see if same action gives the error on it too.

  4. Good call! Attempts to update plugins on another blog of mine result in the same error.

    Hmmm…I was messing with the php.ini file today, could that have done it?

      1. No, I only attempted the plugin updates on an existing WP 2.9 installation which did not have this issue yesterday. Now I tried restoring the default php.ini file and lost all access to the wp backend…the site still works, though.

        1. then try installing new wp 2.9 first and make it work. Once its successful then move on to upgraded ones.

          whats the server that you are using?

          do you have messenger? lemme know ill add ya if you need professional service

          1. I never actually got around to installing a new wp. I switched my php configuration from FastCGI to regular PHP. Then I found the whitespace at the top of my wp-config.php file which was crashing the backend. Once I got back in, I was able to update the plugins and move back to FastCGI. Thanks for pointing me in the right direction!

  5. Sorry didn’t help me, I started getting errors trying to upgrade plugins, first it wanted an FTP user and pass, then it couldn’t find the wp-content directory, now it cant unpack plugins….


    This solution didn’t quite help me, I think there may be a problem on the server side in my case :(

  6. Oops…must have messed with something. Getting new error now. In the admin section I can’t see anything except the below error

    Fatal error: Cannot redeclare class WP_Http in /home/…/public_html/blog/wp-includes/class-http.php on line 38

  7. Recently I started to hate wordpress is incredible sometimes I spend a lot of time fixing stupid problems instead creating content.

  8. Please will you advise how you go about overwriting this file – I manage my own wordpress and dont know how to do this?

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