Excel Crashes when using locals window to view custom-defined class

I create a collection of several instances of this complicated class, but when I expand upon the item in the locals window when debugging, excel crashes (even when the collection contains one item). Please provide some clues to look for.

It is a fairly complicated class that I use in a module that does not seem to have any issues when I define several objects, variables, and arrays. There are several private variables in the class including collections, other custom-defined classes, arrays, and several different variable datatypes. There are also several properties (some read-only some not), subroutines, and functions that all manipulate one or more private variables/objects/arrays at a time.

Since my class is thousands of lines of code long, I have created a testclass that I'm using to crash excel on purpose to give me clues about what to look for. So if you don't have any ideas about what to look for, please provide some clues as to what would crash excel with a simple test class.

Notes:
Windows 8 (not 8.1)
There are no add-ins, Data links, etc.
Virus software and Excel was updated w/i 2 weeks
Only one instance of Excel is installed

A List of private variables:

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...each collection typically has 1-6 CTradeSpread (custom-defined) objects, but I have Collections with over 200 CTradeSpread objects that works perfectly.

Using pre-processor commands, I narrowed down my arrow to the following subroutine and get property.

First... for curious users, this is a brief overview of (how I use) pre-processor commands. If any knowledgeable programmers would like to share other uses of pre-processor commands, I welcome your comments.
For forum users that do not know what preprocessor commands are (as I didn't a week or so ago), they allow some of your code to not run upon initialization by changing a value. It's useful for debugging when you write large blocks of code. For instance,

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Thus... by only changing bool, when you run the code with bool = True a Msgbox would display the string: "Hello World" and with bool = False a Msgbox would display the integer: 42 with a single Msgbox(A) command.

The next post will describe issues I'm having.

After many hours... I have simplified and solved the problem. Now I want to know why.

The following sequence of events with the following code will not crash excel when I view the instance: MyClass1 in the locals window by expanding it (clicking on the "+" that expands and displays all private variables defined in the instance of the class):

1: I step through a subroutine in a module: MySub_InModule() line by line until I set a new instance: Set Inst_MC1 = New MyClass1 (on a separate line from the Dim statement)
2: I expand Inst_MC1 to view all private variables (SUCCESSFULLY)
3: I call subroutine: MySub_InClass using the previously-defined instance: Call Inst_MC1.MySub_InClass(InputToMCSub)
4: I expand Inst_MC1 to view all private variables in the locals window (SUCCESSFULLY)

'/Module: Module1

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'/Class Module: MyClass1

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The difference in the code above and code below is in bold.

The following sequence of events with the following code will crash excel when I view the instance: MyClass1 in the locals window by expanding it (clicking on the "+" that expands and displays all private variables defined in the instance of the class):

1: I step through a subroutine in a module: MySub_InModule() line by line until I set a new instance: Set Inst_MC1 = New MyClass1 (on a separate line from the Dim statement)
2: I expand Inst_MC1 to view all private variables (SUCCESSFULLY)
3: I call subroutine: MySub_InClass using the previously-defined instance: Call Inst_MC1.MySub_InClass(InputToMCSub)
4: I expand Inst_MC1 to view all private variables in the locals window AND EXCEL CRASHES

'/Module: Module1

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'/Class Module: MyClass1

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The read-only property for Int2 is simply:

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More concisely:
Why does pInt2 = pInt2 + Something crash excel but pInt2 = Int2 + Something not crash excel?

(pInt2 is a private read-only variable with Public Property Get Int2() As Integer, defined in a custom-defined class and the operation: pInt2 = Int2 + something/pInt2 = pInt2 + something is performed/defined in a subroutine within which pInt2 is defined)

soooo many hours over a little "p".

Note: My question will be addressed in another thread: http://www.excelforum.com/excel-prog...not-crash.html

Please leave any comments/answers about solving the problem statement in the thread referenced by the above linkback; however, someone wishes to comment about clever uses of pre-processor commands, please do so (unless this thread is updated with a linkback to a thread about pre-processor commands which I may post in the future).