Paid Downloads doesn't work on Mobile Devices

Hi,

bought this wonderful component, but unfortunately
it doesn't work on mobile devices (tested with Android Smartphone and Tablet)

What happens:
The Payment process with Paypal is successful,
then i click at "Download", but Download doesn't start.
There is written "Download failed".
I can reactivate it once more and then a small ***.htm file has been downloaded.

Is there any chance to fix that issue?

thank you, Tomaz.

Can it be that the ChMOD settings of the files-folder is wrong?
But on my PC it works perfect.

The ChMOD of the files-folder is 755 and the file itself is 644

I found out now, that in some Mobile Browsers it works, in some not.

It works in Firefox, Opera Classic
It doesn't work in Android Standard Browser, Dolphin, Next, Chrome