Yes, I just tried to create an account, I have this error message, so maybe use the original .htaccess, It just contains this:

Options -MultiViews -Indexes

<IfModule mod_php5.c>
php_flag allow_url_include Off
php_flag register_globals Off
</IfModule>

<IfModule mod_rewrite.c>
RewriteEngine on
RewriteRule ^m/(.*)$ modules/index.php?r=$1 [QSA,L]
RewriteRule ^page/(.*)$ page.php?i=$1 [QSA,L]
RewriteRule ^s/([a-zA-Z0-9_]+)/([a-zA-Z0-9\.]+) storage.php?o=$1&f=$2 [QSA,L]
</IfModule>

AddType image/svg+xml svg