I've downloaded the trial version 10.4 to test it and compare it to previous versions. I still use versions 8.0, 9.0 and 10.0. During the installation of the trial version, I didn't permit the remove of the older versions. But after the installation and the opening of the trial version, my version 10.0 has been erased and the other two are now trial versions with limited access to some commands. The installation of the latest trial version corrupts the previous ones !
Is this a bug ? How can I recover all my previous versions for which I've paid ? Why does the latest trial one interfere with the others and corrupts them ? What's the purpose of Wolfram to act like this ?
I'm upset, totally upset !