Probably the merged project had a scale conflict with the previous project, so, if you take a look in same groups, you will see a scale of (-inf), try to invert the process, open the second project and import the first one, see if it happens again.
btw: we improved this problem in EIAS 9.
Its a really interesting new research from NVIDIA.. the mix of CPU+GPU distributed simulations over the farm is the future for sure, lots of Pro fluid simulation software are doing this right now..