"Internal Error: Downloading of the variant package failed. Most probably there is a non-commercial software in your device"
Wow! How do I fix this? I had no idea about non-commercial software on my phone.
Searching the net I found a few fellow sufferers but no hint towards a solution. Only some creative methods to reset the phone which didn't help anyone solve the problem.
Here's what fixed the problem for me:
On my machine the download was interrupted about half way through. The complete firmware download would have been 124 MB - my download stopped at 62 MB. Strange thing getting the aformentioned error message during a download. Usually the installer either checks the validity of the device before or after the download but not in the middle.
It happens to be that I have a 64 MB ram disk installed for my temporary internet files. I don't point the system's temp variables to that ram disk - it's really just meant as a browsing cache.
Having mentioned the numbers you can imagine. Instead of using the common temp folder in the user directory OVI Suite caches the file to my ram disk - namely to the temporary files folder of my standard internet browser.
So - if you experience the same problem - check for free browser cache memory.
Good luck.