As systems become more complex it is easier for issues to arise. Below are some methods for attempting to resolve those issues.
Some users enjoy building an entire system before testing any part of it. This is a sure-fire way to hit problems since there are so many variables and settings that might have been omitted or have problematic values.
The best way to build a system in our opinion is to build a section at a time, and test that section to ensure it is actually doing what we want. This gives us the certainty to know this part of the system is working as intended.
Disabling dynsets can be very easy since they are arranged hierarchically. This allows us to turn off major sections to see if the remaining dynsets are in fact working correctly.
Once we identify the dynset(s) who are misbehaving, we know where to focus.
This can help indicate geometry that may be problematic and should be checked for modeling integrity, material issues, etc.
Try running the simulation with a limited selection of imported geometry. This can show if at least those pieces of geo are behaving correctly.
Next, try importing other pieces of geo and see if the system continues to encounter issues or not.
If all these fail, go to How to Get Good Support