Joomla 2.5 404 issues

Question

I have a J2.5site set up that uses language. Thus the urls look something like this:

https://www.mysite.com/en/

and

https://www.mysite.com/en/my-component/

and

https://www.mysite.com/en/my-component/my-alias

I have also set up a script that emails me whenever a 404 or 500 etc occurs:

Here is the result of one (of hundreds):

500 - Error: 500
Invalid controller: name='index', format=''
Call stack

Function Location

1   JSite->dispatch()   /opt/host/apps/joomla/htdocs/index.php:42

2   JError::raiseError()    /opt/host/apps/joomla/htdocs/includes/application.php:208

3   JError::raise() /opt/host/apps/joomla/htdocs/libraries/joomla/error/error.php:251

URL:/en/index.php

Notice the request. If I understand correctly, nothing should ever ask for /en/index.php. since by that time, it has already been interpreted by the entry index.php and therefore appends '/en/'

I am not getting any request errors in my apache logs or any other apache errors.

All that is happening is that I am being bombarded with emails stating that something tried to access http://www.mysite.com/en/index.php or https://www.mysite.com/en/my-component/index.php and thus either generated a 404 or 500 error

Is this spider (search engine bot) issues or is it a server misconfiguration?

Thanks

Jacques