Altera PLL and Altera PLL Dynamic reconfiguration : choose C-counter for two outputs simultaneously.

Good morning,

In order to check how Fractional N-PLL reconfiguration works at simulation , I've generated new project .

The project consists of PLL, RECONFIG_PLL and incoming/outcoming signals. PLL receives 160 MHz at its input and has only one output .

The initial output is 128 MHz, and then changes according to incoming data.

when I've used Fractional N-PLL, then simulation has stuck and stopped after 5000 iterations.

when I've used Integer N=PLL, then simulation works properly.

The TB is same for both N-PLL.

I'm working with ModelSim 10.5 Starter edition.

Why simulation of the Fractional N-PLL is sticking?