I like the idea of Alex's solution but I seem to fight the IDE on occasion when opening modules (random hangs etc) means I can have difficulty finding the code at that address in practice.

Another method I use is to log the Count variable in the FinalizeUnits method using a non breaking breakpoint.

I can then see what is the last number attempted before things blow up in the output window.

I then run again and change the breakpoint to break and on the condition of Count = <whatever the last count was>