Recently had a problem whereby opening a spreadsheet within Excel 2003 would launch the application but the workbook will not open. No error was shown in this case, just the blank grey background. Sometimes this can by the excel.exe remaining open and running as a ‘stuck’ process, which can be resolved by loading Task Manager and killing it. Unfortunately that wasn’t the case this time so looking in to the problem I found it may or may not display an error:
Cannot find the file ‘path’ (or one of its components). Make sure the path and filename are correct and that all required libraries are available.
The problem is caused by the Ignore Other Applications setting being set on. To set it off, choose the menu command Tools->Options, navigate to the General tab, turn off the checkbox “Ignore other applications”, and then click OK.