Hi Pete

Thanks for that, I got that to run!

Although now the top rail and OSB are now bonded, this does not replicate a nailed connection, is there a way of now replicating this? 

I have tried now putting beams to connect the studs to the ground rather than a fully fixed connection, but this is now causing me to exceed the problem limit. How can i get round this? I feel like were so close this now!! My aim is to get a model with sheathing fixed to the studs replicating a nailing pattern around the perimeter of both sheets an the studs being connected to the ground using beams so there is a stiffness on the uplift forces. Is this going to be possible with my size of model?

Kind Regards