It seems many people have had trouble updating their 1.4.4 DL2 to 2.x so they can use
vbus.net. Since I have been poking around on the DL2 for many years I was able to find some of the files that control this and see what they were looking for, and I was able to successfully upgrade to 1.4.7, which is a necessary first step for upgrading to 2.x.
I haven't tried the next step, upgrading to 2.x. Hopefully RESOL's instructions for that are better. Let us know how you do.