Strange error in machine defintion manager (Error occoured in IOF chook: )

Hello everyone,

i got a strange error. i build my machine, everythink works fine. Its a 5 axis head-head machine.
if i want to click on "verify achis" , i got two error messages:
1) Error occoured in IOF Prepare Simulation: "
2) Error occoured in IOF chook:

my machineconfiguration is the following:
Machinebase:
.....table group:
..........mill machine table
.....mill spindle group:
...X
......Y
.........C
.............Z
................A
..................spindle

no toolchanger

i havnt do anything to the Post, its the MPFAN.

what can be the reason for that error ?

greetings
CNDaniel