Nintex Error Help

Hi,

I have a rather large workflow and I am getting the following error. I can't seem to pin point the error as the file it is mentioning is fine!

Any help is appreciated!

Error:

61e4f3f9-30ed-e5b0-0000-000000000000. Details: System.Activities.Statements.WorkflowTerminatedException: Error Code: -1, Microsoft.SharePoint.Client.InvalidClientQueryException, Message: The expression "FileLeafRef eq 'Filename.xlsx'" is not valid.