# D.2 Version 4.0.x

Check-point Files

Version 4 of XTrkCad introduces a new way of handling check-point files. This will allow resuming your work after a system crash much easier than before.

If you start XTrkCad V.4.0.x the first time after an upgrade from a earlier version, a pop-up with the question: "Program was not terminated properly. Do you want to resume working on the previous track plan?"

Select "Ignore" only if you're sure that the work from your last session has been correctly saved. If uncertain or restarting after an earlier failure select "Resume".

Help System

The built in help system has been converted to a much more flexible and widely used HTML format. With many new graphics and extensively rewritten text the help information is now up-to-date with recent development.

Layer Colour Settings

Your personal layer color settings are now stored in your preferences. This allows you to apply the same settings to other layouts you design.

Parameter Files Updated

Thanks to Ralph Boyd, Dwayne Ward, Casey Sterbenz and others, many new and updated parameter files were added to this release.

Wheel mouse

The wheel on a wheel mouse can now be used to zoom in and out on a layout design.