Using the Altera PLL IP

​Hi,

I use Quartus II 15 and Cyclone V. When I try to use the Altera PLL then the Megawizard just stops and dissapears. If I try to use QSYS and instantiate the PLL here then I get two error messages:

Error: can't find package ::altera::generic_pll while executing "package require ::altera::generic_pll"

Error: An instance of Altera PLL could not be created. The component had an unexpected internal error.

Does anybody know what the reason for this is?