All 5 Greater Mass Imbue spells for Shamans show up in the "/outputfile missingspells" list. But these spells are deity-specific, so the only spell that should be listed is the one for your deity (in my case, Amber for Cazic). If you've scribed it, then none of them should be listed. 44 Greater Mass Imbue Amber 44 Greater Mass Imbue Diamond 44 Greater Mass Imbue Ivory 44 Greater Mass Imbue Jade 44 Greater Mass Imbue Sapphire The same problem might exist for Clerics and Druids which have their own deity-specific imbue spells. The older Imbue and the Mass Imbue spells seem to be handled properly, it's just the fairly recent Greater Mass Imbue spells that mistakenly appear on the missing spells list.
I checked the missingspells list for my Wood Elf Druid (Tunare), and it contains the following: Code: 44 Greater Mass Imbue Plains Pebble And I also checked the missingspells list for my High Elf Cleric (Tunare), and it contains the following: Code: 44 Greater Mass Imbue Amber 44 Greater Mass Imbue Black Pearl 44 Greater Mass Imbue Black Sapphire 44 Greater Mass Imbue Diamond 44 Greater Mass Imbue Opal 44 Greater Mass Imbue Peridot 44 Greater Mass Imbue Plains Pebble 44 Greater Mass Imbue Rose Quartz 44 Greater Mass Imbue Ruby 44 Greater Mass Imbue Sapphire 44 Greater Mass Imbue Topaz