I am lost at where the error is coming from as the relevant image has $card in the folder box which should locate this column in the spreadsheet? And all the spreadsheets are local to the psyexp. file.
I went for a workaround (one Excel file and varying selected rows instead of three) and in the process discovered that the issue was blank rows in the chooseRule file. However, I’ve left it as the workaround because it’s more efficient more making changes.