At work I am currently working on a financial model that forecasts a bunch of costs into the future. There is a lot going on in this file, with lookup tables, tons of inputs, a lot of formatting, and all the good stuff, but no massively complicated formulas and very limited use of macros. At around 13000 rows, I noticed that the file was failing to calculate as evidenced by the always present "calculate" in the lower left corner of the screen. So there are a few issues with this model:

I am not sure if the model is simply to big/complex to calculate all the way through or if it is corrupted somehow. I am nearly positive that the formulas are correct. I have tried taking the first line in the model, which consists of some simple formulas to get dates filled out across the sheet, and pasting it all the way to the bottom of the sheet. This results in the "calculate" error message which is surprising. I would think that excel is designed to be able to take a simple formula and calculate it all the way through the maximum amount of rows it allows, so maybe the file is corrupted. However, when I am working with the original model, other than the "calculate" message, I have to reason to think that the model is failing to calculate as the numbers run and the formulas are working (as far as I can tell). Is it possible that I am getting this "calculate" message but that I have nothing actually going wrong with the file?

I personally think that the file is fine and that the numbers are probably correct. I just need to be sure for obvious reasons.