jstl, beans, slight calls

i'm operative jsp where i need methods vigilant bean. before chronicle page does jstl works properly. new chronicle set adult this:

<jsp:usebean id="pagebean" scope="request" type="com.epicentric.page.website.pagebean" />
<c:set var="pagedividers" value="<%= pagebean.getpagedividers() %>" />
<c:set var="numcolumns" value="${pagedividers.size()}" />

the non-static pagedividers list object.

i'm encountering issue: i ask pagedivider's size, an difference thrown. i know rudimentary jtsl blunder -- am i doing wrong?

the blunder summary is:

the duty distance contingency used prefix default namespace specified

how i justly opening methods pagedividers object?