The Iterative Solver stopped. The solver has numerical difficulties. Model may not have adequate fixtures. No results saved.

hello, I designed a elbow 90degree, 64inch.

PSI is 150 (internal pressure).

I have done the fixtures, fixed geometry on the both ends of the elbow.

material properties is done, which is cast iron.

the information was taken from this website: http://www.starpipeproducts.com/pdf/utility/catalog/UCAT1201/flanged.pdf

mesh is good but when i run simulation for the results, it just shows this error "The Iterative Solver stopped. The solver has numerical difficulties. Model may not have adequate fixtures. No results saved"

I have tried everything but still showing this message, i don't know where i am going wrong.

Can someone please have a look at my design and see if there is any problem?

i am uploading the part.

thankyou

SolidworksSimulation