some users of my application got problems with activation key. How can I make it compatible for every device?
If I change their user ID, so that there are no spaces, dashes, capitols, etc... and then I generate the activation key, then it works on the most devices.
I let them enter 1 string for user ID and 1 string for activation key. Then I break the first string to chars and calculate the activation key.
Then I put the new chars together again and create the string, which should be compared with the string they entered.
What could be the problem and how can I solve it? Its not country specific, but device specific.