Hi, I have asked similar question at Missing point charts
If you will skip point for null value line will connect to next available point.
In linked post I gave screen-shot
of possible lines.
I got 3 solutions that may fit your needs.
1: If you have only one line, you may skip those points and line will join rest. As I wrote above. But this solution will not work for multiple lines with empty values. See attached picture
to get idea what may go wrong with multiple lines with missing values.
2: is to set fake value ex: 0 and try to show that point differently. For example setting different label like in Meteo Chart
with devil icons for fake data.
3: Try to split one line with missing values into several lines. This will work only if you have another point in category that has empty value.
As you can see all of above solutions have their limitations. Easiest is 2, but than you may mislead user with fake data.
To Telerik Team, please open this issue or task so that we can vote for that. Otherwise we will have to write hack code to get desired charts.