I have just released a new version of the ClothCalc script with automatic calculation data update completely disabled. As we now need to be more careful about our CPU load, I also included a load check to the code, so that if there is too much load at the moment, the server will refuse to do your calculation. Right now the load limit is very strict and you will likely get refused all the time. I will hopefully make it more friendly in a few hours, but I first need to see how well does it keep the load under control.
TL;DR: update ClothCalc (old versions are intentionally broken) and be patient when trying to update your data.
//update: I already increased the load limit as high as we can afford right now.