what elgg version did you download and are you sure you're using the correct plugin for the correct elgg version?

I have Elgg version: 1.8.4. I didn't download any plugins this is a fresh install. Trying to activate or deactivate any existing pluging that came with the install causes the error. I am able to activate/deactivate all plugins at the same time but can not activate/deactivate any single plugin by itself.

I can add that I did the mor rewrite test with sucessful result.  http://docs.elgg.org/wiki/Mod_rewrite_test

Andrea, does your environment meet the technical requirements?

http://docs.elgg.org/wiki/Installation/Requirements

Hi Kevin. I checked everything again to make sure and yes, my environment meets those requirements. The odd thing is that "activate all" and "deactivate all" works, but changing state of a single plugin doesn't. Could there be something wrong with the url RewriteRules in htaccess?

I have tried installing in root folder and in a subfolder. I get the same problem regardless.

Andrea, so far as I know Elgg's rewrite rules have not changed recently and the application has been installed successfully by thousands of people, so I think the problem is likely related to your server rather than Elgg.

As a first step, I suggest redownloading it and installing from scratch in a new database to make sure that you don't have a corrupted PHP file or database.

"Form is missing __token or __ts fields" ?
so -- the token and/or ts fields are missing !

why ?
-  'bad code' ?
-  post data size too small ?

Also, what versions of Apache/PHP/MySQL are you running?

I exactly got the same problem since I moved to another web hosting shared.

Rewrite mod test works,all seemstowork but dunno why, I can only activate all plugin instead of one by one, or I got :

Form is missing __token or __ts fields

http://94.23.202.*/~hostpfeara/elgg-1.8.4/action/admin/plugins/deactivate?plugin_guids%5B0%5D=2&__elgg_ts=1337088099&__elgg_token=21ee459654da0c05faae67c2bb2aec78

here is the tools used :

MYSQL server

• Version du serveur: 5.0.95
• Version du protocole: 10

WEB Server

• cpsrvd 11.32.2.25
• litespeed
• Version du client MySQL: 5.1.61
• Extension PHP: mysql

phpMyAdmin

• Version: 3.4.10.1

Can someone tell me how to disable this security since it doe'snt work on my server ?

Or can someone tell me what to do to fix that ? 3 days on it and i'm starting to overload..

thanks by advance!

Thank you for trying to help Kevin. I have tried everything I can. Manual install, different scripts to install, different installation locations. I have given up on solving this with my current host and I am moving to another host. Hopefully it will work better!