Callstack that has has AV reported I see FunctionName() + some Hex value?

Question

What is this offset hex value?

Answer 1

I believe this will be the offset of the instruction from the start of the function.

If you have the assembler (.asm) output for your application, from the compiler, you can map the offset value (once you locate the function) against this to determine what instructions were being executed. If the correct flags in the compiler configuration are set the .asm output will include the high level language constructs (e.g. C/C++ source) that the assembler represents. You will then be able to pinpoint the statement being executed.

If you are using a different language than C/C++ for your application then the above will still apply but you may need to review your platform documentation to achieve the necessary output.