If during installation "load perspectives automatically with Excel" option is checked and Perspectives/Excel is launched via Start > All Programs > IBM Cognos > TM1 > Perspectives for MS Excel then the following is observed:
- Excel launches
- TM1 Perspectives splash screen displays
- Excel error message "Run-time error '1004': Method 'Open' of object 'Workbooks' failed"
- Only option is to click End in the error dialog. No TM1 ribbon.
- If Perspectives is subsequently launched via the start menu then it opens no problem.
- If rather than opening Excel / Perspectives via Perspectives shortcut but rather Start > All Programs > Microsoft Office > Microsoft Excel 2010 then Excel and Perspectives both launch successfully.
- If the IBM Cognos TM1 Perspectives add-in is deselected in the Excel add-ins dialog then Excel / Perspectives launches normally without error by selecting Perspectives via the start menu.
- If the IBM Cognos TM1 Perspectives add-in is deselected in the Excel add-ins dialog then Perspectives launches normally via the start menu if Excel is already open.
My interpretation is that the error is returned because Excel (or the OS) is trying to launch Perspectives a 2nd time when tm1p.xla is already open (... I don't think there is any other conclusion

Has anyone else seen this and can confirm? Is there any known technical resolution? Is there an APAR with IBM?
(Yes users could be trained to either have Perspectives auto load and use the Excel shortcut only or to not auto load Perspectives and launch via the Perspectives shortcut. But really it shouldn't make a difference how the application is launched and if this can't be solved it is only going to cause frustration for users and noise for support.)