Problem with installing Qubicle via Steam



I have Qubicle Demo which I installed by use of Steam. Now, I want to buy Qubicle Indie Edition via Steam.
When I choose “Qubicle Voxel Editor”, there is option to download – I click download and then I can see option to execute Qubicle (I have already installed it).
When I choose “Qubicle Professional Licence”, there is a message that this content requaries basic version Qubicle Voxel Editor on Steam to run correctly. But I installed Qubicle Demo before (and it is working).
It is impossible to me to install commercial version of Qubicle via Steam. Please, help.



Id first check out the “Learn” database here:

In addition, Id search this forum (where we are currently talking) to see if anyone has already asked this question.

If those 2 do not solve your issue, then Id contact the developer here: