Revit imposes undocumented limits on hatch pattern scale. The first message arises when some element within the pattern is too small - Revit's smallest line length is 1/32" and that is quite a reasonable restriction. The second message, issued when a pattern has elements with repeat distances greater than about 70 feet, is less understandable.
FAQ - What are the limits on Revit pattern scale?
The upper scaling limit can be avoided by using the HatchKit Add-In for Revit to load patterns. Without the Add-In HatchKit can adjust hatch pattern elements to fall within Revit's scaling limits when loaded with 1:1 scaling.
Hugh Adamson
www.hatchkit.com.au