I have a Bubble series with many data points and custom markers, sometimes over 2500. In those cases, the chart generation fails. I have also tried using the default markers with no success. I also see the same issues when using Scatter as well. I attached a sample project that you provided regarding one of my previous questions since it suited my situation nicely, and all I had to do was increase the number of data points. I documented my findings in the ViewController.m file, as well as below. I am using the latest OSX, Xcode, and iOS, and 2014.1.

1. Single BubbleSeries and custom markers with a lot of data points.

- Only add _firstSource to the chart.

- Increase number of data points to 2500.

- Error on startup: EXC_BAD_ACCESS

2. I thought Issue #1 may have been caused by custom markers, but not so.

- Remove the chart delegate setting so that custom markers are not used.

- Only add _firstSource to the chart.

- Keep number of data points at 2500.

- Error on startup: EXC_BAD_ACCESS

- And if no error on startup, then it definitely occurs on rotation: EXC_BAD_ACCESS

- If not the EXC_BAD_ACCESS error, then it is a "iGChart_LegendWithCustomMarkers(58695,0x243e1a8) malloc: *** error for object 0x106dfcd4: incorrect checksum for freed object - object was probably modified after being freed." 

3. Then I though maybe it was just Bubble, and so I tried Scatter, but not so.

- Change to Scatter helper and series.

- Only add the _firstSource to the chart.

- Keep delegate set so custom markers are still used, but make sure to hard code the radius since there is no IGBubblePoint anymore

- Same error on startup: iGChart_LegendWithCustomMarkers(58808,0x243e1a8) malloc: *** error for object 0xaf5aac4: incorrect checksum for freed object - object was probably modified after being freed.

4. The same thing happens with Scatter and no custom markers, just like case #2.

5. The only thing I found to work was to use Scatter with no custom markers, AND NO DEFAULT MARKER, whenever a series had a data with over 2000 data points.

- Keep Scatter, 2500 points, but remove chart delegate setting, and set marker type to IGMarkerTypeNone.

- The IGMarkerTypeNone solution (hack) only works for Scatter. It didn't seem to work when using Bubble series.

- I also use a trendline, so not having the markers show is not a deal breaker, but also not ideal.

So what I've been doing is checking to see if any of my series have more than 2000 data points, then I switch to no custom markers and IGMarkerTypeNone on that particular series. Otherwise I can use the Bubble or Scatter as intended with custom markers. If I lower the number of data points per series to something usually under 2000, it generally works fine, but I'm not 100% sure about this.