When a formula requires a cross-sheet cell reference, the usual syntax is something like:
```
IF(Sheet2!A1>Sheet2!A2,"bigger","smaller")
```
But when the sheet name has spaces, the sheet names must be wrapped by single quotes:
```
=IF('Sheet 3'!A2>'Sheet 3'!A3,"bigger","smaller")
```
And this seems not to be supported by the CalcEngine module.
In attachment: an Excel file where the cell A1 is correctly computed, whether accessing the cell A2 causes an exception.
```
IF(Sheet2!A1>Sheet2!A2,"bigger","smaller")
```
But when the sheet name has spaces, the sheet names must be wrapped by single quotes:
```
=IF('Sheet 3'!A2>'Sheet 3'!A3,"bigger","smaller")
```
And this seems not to be supported by the CalcEngine module.
In attachment: an Excel file where the cell A1 is correctly computed, whether accessing the cell A2 causes an exception.