Problem with inverse kinematics in OpenSim 4.5

[Tereza Kasparova]

Hello,
I am having a struggle with IK on my computer. I am not sure if it is related to the fact that I am using a Mac, but while processing the IK the frames are processed smoothly, and all of a sudden the processing speeds up, resulting in gaps of unprocessed frames that are stuck at a certain value. When I plot the data with Matlab, the final graph has visible gaps. I tried to process the data several times, but the problem persists. My supervisor also checked the trc. data and the model, but everything seems to be fine. So I assume an issue is probably in my computer/OpenSim. I have attached the Matlab-generated figure to illustrate my issue. Have you ever encountered such an issue or could you maybe suggest what could be its cause?

Thank you in advance for any help.
Tereza