If you do an upgrade of DxO Optics Pro 5 on a Mac with Snow Leopard (10.6) you may get the following error message:
The solution for this error is rather simple:
“Run the download manager and choose the install on another computer option. This will place an install folder on your computer. Then run the installer in the install folder to replace the older version of Optics Pro.”
This solution was provided by DxO Support and worked well for me so I thought I would share.