I got panic for a while when I cannot transfer to photoshop the photo i wanted to edit using the short cut Alt + P in DPP. I thought I pressed the wrong short cut, and thus i decided to do it the manual way by clicking on Tools -> Transfer to Photoshop. Deng it still fail !
I have been into this situation before, what I did was to make sure Photoshop is my default application to open *.TIF. After that it's all back to normal again. So I decided to blog it and so I'll had it permanently.