From the style name, I assume you are working in a metric drawing. Using the Architectural Building Model and View (Metric - stb).dwt template to start a new file with base units of millimeters and the out-of-the-box Concrete-200 wall style, I was able to set MaxHatch to 100000 and still have a 100-meter-long wall display the hatch in the Medium Detail display configuration [plan hatch = Concrete_C, scale 100.00]. A MaxHatch setting of 1000000 allowed the hatch to display in the High Detail display configuration [plan hatch = Concrete_C, scale 50.00].
Do all of your settings match the ones I listed? Are you drawing longer walls? Are you using a different base unit [such as 1 meter], but do not have scaling of objects inserted from another drawing turned on? If so, the hatch scale factors used by the Concrete.Cast-in-Place.Flat.Grey material will not be scaled down by 1000 to adjust for the difference in units. [Then again, the wall will be 200 meters wide, so that would not be a good idea.]
--
David Koch
Member of the Autodesk Discussion Forum Moderator Program