Hmmmm.

This is one of those errors that "shouldn't occur" - no one's ever seen one of those, have they? (in Ping Plotter or any other application - ha!)

So, basically what this is saying is something in the application is trying to access a piece of data for a hop that hasn't been collected yet.

This might be that an individual hop isn't responding (or timing out) and the engine isn't properly checking someplace. If this is the problem, there are a couple of things to change that might address things. First, change your "Timeout speed" (in Edit / Advanced Options / Packet Options) to something smaller. Most networks work will with 1000 ms - but in a few you need more. Having a high number here shouldn't cause the problems you're seeing - but for "unplanned problems", it's hard to say.

The next possible option is that you have the maximum number of samples to hold in memory set to something besides 0 (all), and Ping Plotter is somehow trimming off samples at an inoportune time. If this is the case, try setting this option (Edit / Advanced Options / Auto-Save / Maximum samples to hold in memory) back to 0.

These are just two ideas on how to affect this.

Another thing to try is to download the latest beta version - as this reworks some of the internal architecture that might be contributing to this error message. Please contact me at pete@pingplotter.com for details on this.