When trying to run a simulation using Arc Length control method I continually get the following warning pop up:

'No. of pre-solving operations for Direct Sparse Solver could be high. Would you like to switch to Large Problem Direct Sparse to speed up the process?'

My understanding is that large problem direct sparse does not work with arc length control?

If I select yes than the warning continually pops up and the simulation goes no where. If I select no than after a period the following error pops up:

'Exception code 0xc0000005 thrown at address 0x945e9d4a in: Nstar.dll file version 30,1,0,7itch to Large Problem Direct Sparse to speed up the process? "No". Please press OK to terminate solution'

My questions are:

• What is the most effective solver to use with the arc length control method and why?
• How do I get around the cyclical warning message about the large problem direct sparse solver?
• Is the 'Exception code' error message a memory issue and if so how do I work around it?

I should add that I have run other simulations with models that are larger, have more degrees of freedom whilst using the same solver and control methods with no issues. In saying that, I have had the error message pop up on smaller models previously.

When running all models using force control method the simulation has completed.