Hello, I am trying to display a surface using the Actions > Surface>Show menu. The surface is not displaying and the following error is in the reply: C:\Program Files (x86)\Chimera\bin\mscalc.exe 1.400000 2.000000 1 Calculation of some surface components failed (code 5). Falling back to single-component calculation. C:\Program Files (x86)\Chimera\bin\mscalc.exe 1.400000 2.000000 0 Surface calculation failed, mscalc returned code 5 I am using Chimera version: production version 1 build 2540 2008/07/09 Platform is Windows Vista 64 bit. The file I am working with contains 2 subunits. If I split the two subunits into separate files and open individually in the same session, the surfaces display without any issue. I am trying to show the surface of the two subunits associated, not the surface of each individual subunit. Any help will be appreciated. Cheers, Chuck