You’re missing an existence check (exists, help, harm) on the mouseover condition so it assumes a mouseover unit exists and doesn’t advance past that test.
#showtooltip
/cast [@focus,help,nodead] [@mouseover,help,nodead] [@Mintybear,help,nodead] [] Innervate
You’re going overkill on your target test which is causing the spell to not appear when you don’t have a harmful, non-dead target selected. Use this template instead: