Unable to access Workflow Inventory after upgrade into version 3.2.4.20

ISSUE

After upgrade into Nintex Workflow 2013 version 3.2.4.20, user unable to access the Workflow Inventory page. 

ERROR CODE

From ULS Logs nintexworkflow_workflowgallery_aspx.ProcessRequest(HttpContext context) at System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute() at System.Web.HttpApplication.ExecuteStep(IExecutionStep step, Boolean& completedSynchronously)

RESOLUTION

This is a known issue and the hot fix version 3.2.4.22 has been released.