Thanks for your reply but my original question was not related to
How can I redirect from wordpress login screen to question/answer site?
The site appears to work normally apart from when I click on a username. Then I get a 404 message.
These are my main settings:
http//xxx/test1 = wordpress installation
http://xxx/test1/q2a = q2a installation
URL structure selected from admin center = /index.php?qa=123&qa_1=why-do-birds-sing
Selecting any user links for example 'guest' gives a link
http://xxx/test1/q2a/user/guest and 404 Not Found error message.
I have tried various changes to .htaccess - but I am really guessing what is happening..
DirectoryIndex index.php
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteBase /test1/q2a/
RewriteCond %{REQUEST_URI} ^(.*)//(.*)$
RewriteRule . %1/%2 [R=301,L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^.*$ /qa/index.php?qa-rewrite=$0&%{QUERY_STRING} [L]
</IfModule>
but still get a 404 message.
Thanks for any help you can give.