I just discovered a weird event. Instead of clicking on Ok to close the window with the warningt "this product is not permitted.. etc" I left it open and moves the mouse over the icon in the task bar where I discovered a second window showing the usual CCleaner minimised , beside the minimised window of "this product is not permitted.. etc.." I clicked on the second window and CCleaner showed up, fully functionnally! I was able cleaning, and everything else. The only thing I am not allowed to do, is closing the window with the warning, as both windows disappear together.
Maybe this can help the developpers finding a solution to this problem?
I can not make a screenshot of the 2 minimised windows, the moment I don't move the mouse over it, they disappear!