I had a little problem with a boss extrude from a solid body today that I couldn't find anything in a search for, so I wanted to share it here in case someone else has the same problem.  Heck, I may be searching for it again next month.

When trying to extrude a boss, I got the much-loathed "Operation failed due to geometric condition" error message.  I was able to get around it simply by unchecking the "Merge result" option, extruding the boss, and then using "Combine" to merge the bodies instead.  That's it.  Very easy.

Hope this helps someone else out there. :-)

Scott