There is no limit per se. The important thing is that your code must be minimal with respect to the problem that you are trying to solve. This is not always obvious, so you have to do some research into the nature of the exact problem you are having. For example, a complex set of calculations may be failing because of a numerical rounding issue in one step. Once you have identified that step, you can create code that demonstrates just that issue.
If you have a problem that involves a single operation with a lot of variables, work to determine which of those variables contribute to the problem. You can likely "zero", set to default, or otherwise simplify the rest of the values for your example. As an analogy, if you want to build a house to demonstrate a roof leak, you don't care about the carpet. There's no need to specify the operations to select an appropriate size, color, texture, height, fabric, etc. Just throw in a basic towel you can get off the shelf at any housewares shop and move on.
If you can't find a way to simplify your code and don't have any idea why it might be failing (debug my wall of code), you aren't ready to post on a Stack Exchange site.