TypeError: c.tooltipContainer is null

[jorge Power]

I am getting this error for my line chart for the tooltips:

Error: Unable to get property 'fadeOut' of undefined or null reference

In IE it has a cow. In firefox and chrome it gets ignored but can be seen in debugger.

Here is what debugger says:

TypeError:  c.tooltipContainer is null

I have a line chart that i update every 2 seconds with new data. 

I call chart.clear before i make the chart again with new data.  

The problem started after i added the clear to save memory because the site kept growing in memory. 

Is this due to the fact that a user could be highlighting a tool tip when i call clear that wipes the chart briefly? creating a null chart object?

i have IE 11 and  elycharts 2.1.6 min.

[jorge Power]

Here is a jsfiddle example.

http://jsfiddle.net/Lbjxcg6m/