Some more weird things are happening:
1. VBA editor does not display any code for any spreadsheet currently
open in Excel. (In Excel, Tools Macro Visual Basic Editor. It does
open the editor but nothing in it to work with, cannot even see
anything in the Properties pane)
2. It seems any change to ANY cell on the spreadsheet will trigger the
alert. But the If condition clearly specified the locations being
watched: (Target.Column = 3 Or Target.Column = 9) And Target.Row 25
And Target.Row <= textRow
3. When I stepped through the code in debugging mode, the execution
went through the GoTo statement at all times, i.e. wrongPoolEntry,
regardless of whether the If conditions are met

I think 2 and 3 are somehow related