Two possible reasons I can think of currently:

1. You've installed your site in a subdirectory of your document root path but have not adjusted the RewriteBase variable in Elgg's .htaccess file accordingly. In this case, open the .htaccess file and make this adjustment now. There's some explanation in the .htaccess file what you have RewriteBase set to.

2. You've installed your site using an url with "www" as site url and you try to access it now without "www" or the other way round. In this case you should add the suitable rewrite rule to .htaccess as described at http://learn.elgg.org/en/1.9/appendix/faqs.html?highlight=www#login-token-mismatch.

thanks for the answer,

1.- RJ, server guys said me that there is no problem with the specifications

i'm going to give elgg to server guys and make them install to be sure that server specifications are ok

2.- iionly, i'm trying it into a sudbomain which is in a subdirectory, I installed elgg (1.7 and 1.8) many times before in subdomains and it never happened to me,

anyway I went to .htaccess

# REWRITE RULES

<IfModule mod_rewrite.c>

RewriteEngine on

# If Elgg is in a subdirectory on your site, you might need to add a RewriteBase line
# containing the path from your site root to elgg's root. e.g. If your site is
# http://example.com/ and Elgg is in http://example.com/sites/elgg/, you might need
#
RewriteBase /web/elgg/    - this one is the one i've changed, but nothing happened
#
# here, only without the # in front.
#
# If you're not running Elgg in a subdirectory on your site, but still getting lots
# of 404 errors beyond the front page, you could instead try:
#
#RewriteBase /

i tried putting /web/elgg/ ,  /elgg/  , /root/web/

but none makes any change

i tried to install elgg 1.8 and i could follow further the 1st step

any suggestion?

server staff have installed it and they touch nothing about code and it success at the first time, i've tryed it 5 times and I failed eveytime with the same problem i wrote before x( !!!!

there's something about elgg I can't understand,

what kind of whitchcraft is this!

ya lo hice, de hecho lo intenté incluso creando un nuevo subdominio por ser lo más pejiguero posible y nada.

Podría ser problema del hosting, esta semana lo intentaré en otro a ver si tengo más suerte

en otro hosting no he tenido problemas de momento, ... sigo sin saber porque es el error. Pero al menos lo puedo capear con una redirección

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