FDK errors of Kinematic analysis failed in time step 0

Hello guys,
I tried to implement FDK features to the ankle-joint.
Firstly, I chose only one DOF for FDK which is the rotation of Z, like this:

And it runs well but the AnkleForceDep is too high. I want know how I can reduce the ankle force.
Secondly, when I choose another DOF which is the rotation of Y, it have many errors like this:

I want to know what can I do to run the FDK.
Thanks for your effort .
Greetings,
Xiao Yiba

Dear Xiao Yiba,

It will be nice if you can let us know your information(organization name, lab name and so on) as well as your working environment( AnyBody version ).

Also if you want to get our advice, then please post on the general forum:
http://forum.anyscript.org/forumdisplay.php?f=31

I dont know how you implement some necessary elements near your ankle joint but there are something that we can think of in order to implment the FDK degrees of freedom in the ankle joint.

You need to define prpoer contacts between bone geometries as well as some stiffness around the ankle joint. If you don’t prepare these elements, then solving FDK is not easy.

Also at the moment, we don’t have any reference (literatures) which are relevant for your research.

If you can upload your model in the forum’s debug section, then we may try to have a look at it.

Regards,
Moon

P.S) Please write only one post at a time so that we are not confused with multiple posts.