Hi Stefan,
Why are trying to install 10.1.1 release now? Don't you want to install 10.1.2 release?
Did you check the content of the following files?
$SPECROOT/Install-Tools/.history file: (example from my machine)
10.1.0.0.237 04/05/2016 15:19
10.1.1.0.64 04/05/2016 16:11
$SPECROOT/Install-Tools/.install_history file (example from my machine)
10.1.0.0.237 04/05/2016 15:19 ,,SUCCESS
10.1.1.0.64 04/05/2016 16:11 ,,SUCCESS
Thanks,
Silvio