I am trying to evaluate whether Spire.XLS is going to meet our requirements. Firstly, it handles calculations of formulas so it is already ahead of the competition that I have evaluated. However, I am coming across a very frustrating issue that I need to resolve.
I have a spreadsheet with lots of formulas and named ranges, at least 5 sheets of formulas. When I execute Workbook.CalculateAllValue() my code waits for a little while (so it is calculating formulas) and then throws an exception with the following message:
Key cannot be null. Parameter name: key
But it doesn't tell me where this problem occurs so I have no idea what formula is causing the problem if ant, the workbook is calculated correctly by Excel and the formula validation in Excel shows no formula with an error.
Any ideas how I can track down at what stage CalculateAllValue() is failing. Also, once it fails the calculation engine appears to be permanently broken as it will no longer calculate any formula values.