<html><head><meta http-equiv="content-type" content="text/html; charset=us-ascii"></head><body style="overflow-wrap: break-word; -webkit-nbsp-mode: space; line-break: after-white-space;"><div><br></div> I'm sorry for not getting back to you sooner. I have attached a working version of your code. Since you were missing <div><br></div><div> use petscdmcomposite</div><div><br></div><div>the compiler could not generate the correct call to DMCompositeGetGlobalISs()</div><div><br></div><div> Barry</div><div><br><div></div></div></body></html>