Drupal does not detect an installed module

I have a number of sites running off a single Drupal core installation.

This includes a number of 'standard' modules such as Views and CCK in the /sites/all/modules directory.

This works fine apart from one issue.

One of the sites refuses to accept that the Google Analytics module is installed. It can see all the other modules in the directory, and all the other sites see and use the Analytics module without any issue.

I've tried clearing the cache and checked the permissions but the fact the module works for other sites, and the problem site can see the other modules has got me stumped.

Any ideas?

Edit : Ok, case closed. It was me being a muppet. I forgot the first rule, which is check all your开发者_开发知识库 assumptions. In this case I assumed I was looking at the right site. Wrong. For reasons best kept to myself, I have 2 instances of this site hosted, one of which the domain name resolves to, and one which it doesn't. I was looking at the 'orphan' site's drupal installation, not the correct installation which works perfectly.... now I've actually installed the module.

Sorry to have wasted your time, but rest assured, I wasted far more or my own time, and hopefully this question will serve as a reminder to others to check their assumptions too :-)

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I'm not sure if you mean that this module is not showing up in the modules list, or that it is not showing any data from this particular instance after it is enabled.

If this is a case where the module is installed but not working properly you should make sure that you have not removed the

<?php print $closure ?>

tag from the end of the theme for that particular instance of drupal. If it is removed then the GA javascript code will not be added to the page.

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The only thing I can think of is that there are some missing files; in particular, if the .info file is missing, the module is not listed in the modules page. The same is true if the .module file is missing.

It's not a problem with the permission, as users who can access the page listing all the modules will see all the modules (with the exception of the modules with missing files).