I have created a Web form for Case entity that has a lookup for Account entity. Now clicking on that Account lookup doesn't open the lookup modal popup. Instead of that the entire screen fades out. The issue is same for all the lookup fields.
I have given all the required Entity Permissions to view the lookup entity. Just to be sure I also tried removing Entity Permissions, still the issue didn't go.I have also tried rendering the Entity form on the web-page with no success.
I would like to know am I missing any configuration or is it related to Portal Provisioning. Its a Custom Portal that I have created.
Below is the screenshot of the behavior :
Clicking on the Search Icon grey out the screen as below :
