I have been playing a modified enhanced set, mostly with  units cut.  A few unit modifications but SM remains all default. Playing enhanced AI (default, no AI mods) and Victory goal is capital kill.  The error is intermittent, sometimes SM makes it to detonation then results in normal missile miss or strike. The error calls for game exit. Once I solved by reloading and disbanding the SM but cannot if the unit's turn is over in saved state.

Any thoughts? 

Thought: try it with an unmodified game, that is the supported configuration.

If you have a repeatable case, feel free to send it to me along with the mod.