I did try the obvious variations. The "D" is the standard used to indicate domain spells for divine spellcasters.
I get the same result using the linked stat block above specifically:
[0] (1) Cultist CR 2
[0] (2) XP 600
[0] (3) Human cleric 3
[0] (4) NE Medium humanoid (human)
[0] (5) Init +6; Senses Perception +2
[0] (6) DEFENSE
[0] (7) AC 16, touch 12, flat-footed 14 (+4 armor, +2 Dex)
[0] (8) hp 16 (3d8+3)
[0] (9) Fort +4, Ref +3, Will +5
[0] (10) OFFENSE
[0] (11) Speed 30 ft.
[0] (12) Melee mwk short sword +5 (1d6+1/19-20)
[0] (13) Ranged heavy crossbow +4 (1d10/19-20)
[0] (14) Special Attacks channel negative energy 3/day (DC 11, 2d6)
[0] (15) Domain Spell-Like Abilities (CL 3rd; concentration +5)
[0] (16) 5/day--bleeding touch, copycat (3 rounds)
[0] (17) Spells Prepared (CL 3rd; concentration +5)
[0] (18) 2nd--cat's grace, invisibilityD, undetectable alignment
[0] (19) 1st--command, disguise selfD, poisoned egg, shield of faith
[0] (20) 0 (at will)--bleed (DC 12), guidance, light, mending
[0] (21) D Domain spell; Domains Death, Trickery
[0] (22) STATISTICS
[0] (23) Str 12, Dex 15, Con 13, Int 10, Wis 14, Cha 10
[0] (24) Base Atk +2; CMB +3; CMD 15
[0] (25) Feats Improved Initiative, Stealthy, Weapon Finesse
[0] (26) Skills Acrobatics +4, Bluff +5, Escape Artist +4, Knowledge (local) +3, Knowledge (religion) +4, Sleight of Hand +4, Stealth +9
[0] (27) Languages Common
[0] (28) SQ aura
[0] (29) Combat Gear acid flask (3); Other Gear +1 studded leather, heavy crossbow with 10 bolts, masterwork short sword, black mask, egg
[0] (30) ABOUT
[0] (31) As the most proactive worshipers, the Cult embraces its patron's role as god of murder. Many members hold conventional jobs and social positions, staying close to those they slaughter in the guise of business partners, maids, or military commanders.
[0] Creature Name Line: Cultist CR 2
[0] GENERAL: Cultist
[0] GENERAL: ok doing defense
[0] GENERAL: ok doing offense
[0] GENERAL: ok doing attacks
[0] GENERAL: ok doing special attacks
[0] GENERAL: ok doing tactics
[0] GENERAL: ok doing statistics
[0] GENERAL: ok doing feats/skills
[0] GENERAL: ok doing equipment
[0] GENERAL: ok doing ecology
[0] GENERAL: ok doing special abilities
If I edit to remove the "D" it still fails in the same way.
Since the error message references "parameter 1" which appears to be spellNode, I think the error may be that the variable here should be libNode. As this is my first look at the code & I'm not familiar with this language, hopefully the programmer can quickly debug it.
The later spell parseing code looks for superscript "D" to strip out, this is not preserved when copy/pasteing into the input window, trying it myself from the pfsrd page loses the superscript formatting the code is looking for. Does FGU support superscript at all? I could live with some manual editing to clean up the names to get the code minimally working, once the first problem is sorted out.