Why is version-less spring-security.xsd missing on http://www.springframework.org/schema/security?
<p>In our Spring-based application, we supplement the application context file with elements from namespace <code>http://www.springframework.org/schema/security</code> located at <a href="http://www.springframework.org/schema/security/spring-security.xsd" rel="nofollow noreferrer">http://www.springframework.org/schema/security/spring-security.xsd</a>:</p>

<pre><code>&lt;beans ...
       xmlns:security="http://www.springframework.org/schema/security"
       ...
       xsi:schemaLocation="...
        http://www.springframework.org/schema/security
        http://www.springframework.org/schema/security/spring-security.xsd"&gt; ... &lt;/beans&gt;
</code></pre>

<p>However, recently we receive this error message</p>

<pre><code>Multiple annotations found at this line:
            - cvc-complex-type.2.4.c: The matching wildcard is strict, but no declaration can be found for element 'security:global-method-security'.
            - schema_reference.4: Failed to read schema document 'http://www.springframework.org/schema/security/spring-security.xsd', because 1) could not 
             find the document; 2) the document could not be read; 3) the root element of the document is not &lt;xsd:schema&gt;.
</code></pre>

<p>when opening the application context file in the XML editor of Eclipse after an initial setup of our project or after clearing the network cache of Eclipse. </p>

<p>Further research on archive.org reveals that the version-less XSD has been removed when the now current version (<code>spring-security-4.1.xsd</code>) has been published on or about 2016-03-08.</p>

<p>Does anyone have an idea whether this has happened by accident or whether there is a deeper reason for the removal? For other namespaces, there are still version-less XSDs available on springframework.org/schema/, i.e. spring-security-oauth.xsd and spring-beans.xsd. (Due to my low reputation level, I am unable to post explicit links to them.)</p>

<p>As a workaround, we now reference a versioned XSD. However, until now, my impression was that Spring encourages the usage of the version-less XSDs, for example as suggested in the <a href="http://docs.spring.io/spring-security/site/docs/4.1.0.RELEASE/reference/htmlsingle/#introduction-2" rel="nofollow noreferrer">current Spring security reference documentation</a> or in <a href="https://stackoverflow.com/a/20900801/6376077">this SO post</a>.</p>