SummaryThe following error might appear frequently in web front-end logs: Load control template file /_controltemplates/NWLOnlineComponents.ascx failed: The expression prefix 'NWLResources' was not recognized. The error does not appear to have any impact on workflows.
Ensure that NWLOnlineComponents.ascx has been added to the web application's web.config.
To have the entry added to the web.config you need to activate the web application, using the Nintex Workflow "Web Application Activation" page, for the appropriate web application.
SharePoint does not care which web applications have been activated, it expects all control templates on disk to have an entry in each web application's web.config as the file system is shared amongst all web applications.
Nintex has no control over this except to provide a way to add the entry to the web.config. If you do not activate the web application using the "Web Application Activation" page, this error will persist.
Our recommendation is to use the "Web Application Activation" to ensure the entry is present in each web application's web.config.