Why does modelFit from DRC package gives "no test available" for me?

I have a DRC object LL4 obtained by using drm with LL.4(fixed=c(NA,0,100,NA)) etc, for 5 different treatments. However, when I run modelFit(LL4) just like it is shown in the DRC manual, it...

10 October 2018 8,033 2 View