PROBLEM

When you click the spyglass icon in a lookup cell, the Lookup window appears but you might not be able to select a lookup value.

CAUSE

This problem occurs in embedded related lists Conga Grids. This is an issue with legacy Visualforce pages created with the Conga Grid setup wizards for embedded related lists.

WORKAROUND

A solution is to change the showHeader attribute in the Visualforce markup code from false to true. This adds the necessary JavaScript code from Salesforce to ensure that the spyglass icon works correctly. The change does not display the Salesforce header while embedded in a page layout.