I am viewing the capture_wrapup_start scene multiple times by talking with Duncan again, resulting in viewing the guilds_meeting_start scene multiple times.

In  ~/strive-conquest-linux/assets/data/events/caprute_wrapup.gd  it is possible to talk to Duncan at the guild multiple times, and so the add_timed_event function of capture_wrapup_3 happens once for each conversation.

capture_wrapup_3 (also capture_wrapup_1 if that is your path) has the order to code = 'complete_quest', value = 'princess_search' which should mean talking to Duncan again starts the normal conversation, somewhere this is failing. 

The capture_wrapup_start function is available in ~/strive-conquest-linux/assets/data/scenedata.gd. It is set to start the scene if the princess_quest is at stages 4 or 5.

capture_wrapup_3 = {
image = null, tags = ['dialogue_scene'], reqs = [], character = 'duncan',
text = [{text = "PRE_ANASTASIA_EXECUTION_9", reqs = [], previous_dialogue_option = 2},
{text = "PRE_ANASTASIA_EXECUTION_10", reqs = [], previous_dialogue_option = 3}],
common_effects = [{code = 'add_timed_event', value = "guilds_meeting_start", 
args = [{type = 'add_to_date', date = [1,1], hour = 1}]}], 
options = [ {
code = 'close',
text = "DIALOGUECLOSE",
reqs = [],
    dialogue_argument = 3,
type = 'next_dialogue',
bonus_effects = [{code = 'complete_quest', value = 'princess_search'}]
} ],
},

capture_wrapup_start = {
variations = [
{
reqs = [{type = 'decision', value = 'PrincessDead', check = true}],
image = null, tags = ['dialogue_scene'], character = 'duncan',
text = [{text = "PRE_ANASTASIA_EXECUTION_1", reqs = [], previous_dialogue_option = 0},
{text = "PRE_ANASTASIA_EXECUTION_2", reqs = [{type = 'decision', value = 'SiegeLostSupplies', check = true}], previous_dialogue_option = 1},
{text = "PRE_ANASTASIA_EXECUTION_3", reqs = [{type = 'decision', value = 'SiegeLostSupplies', check = false}], previous_dialogue_option = 1}],
options = [ {
code = 'capture_wrapup_start', text = "PRE_ANASTASIA_EXECUTION_OPTION_1", 
reqs = [{type = 'decision', value = 'aire_is_saved', check = true}], dialogue_argument = 1, remove_after_first_use = true,
}, {
code = 'capture_wrapup_1', text = "PRE_ANASTASIA_EXECUTION_OPTION_2", reqs = [], dialogue_argument = 2, type = 'next_dialogue'
}, {
code = 'capture_wrapup_1', text = "PRE_ANASTASIA_EXECUTION_OPTION_3", reqs = [], dialogue_argument = 3, type = 'next_dialogue'
}],
}, 
{
reqs = [{type = 'decision', value = 'PrincessDead', check = false}],
image = null, tags = ['dialogue_scene'], character = 'duncan',
text = [{text = "PRE_ANASTASIA_EXECUTION_5", reqs = [], previous_dialogue_option = 0},
{text = "PRE_ANASTASIA_EXECUTION_7", reqs = [], previous_dialogue_option = 4},
{text = "PRE_ANASTASIA_EXECUTION_8", reqs = [], previous_dialogue_option = 5}],
options = [ {
code = 'capture_wrapup_2', text = "PRE_ANASTASIA_EXECUTION_OPTION_4", 
reqs = [], dialogue_argument = 1
}, {
code = 'capture_wrapup_3', text = "PRE_ANASTASIA_EXECUTION_OPTION_5", reqs = [], dialogue_argument = 2, type = 'next_dialogue'  
}, {
code = 'capture_wrapup_3', text = "PRE_ANASTASIA_EXECUTION_OPTION_6", reqs = [], dialogue_argument = 3, type = 'next_dialogue'  
}],
}
]
},

var dialogue_inits = {
fighters_init = [
##skipped the not relevant code

{
code = 'default',
name = "Meet Leader",
reqs = [{type = 'active_quest_stage', value = 'princess_search', stage = 'stage4'}],
target = 'capture_wrapup_start',
target_option = 0,
},
{
code = 'default',
name = "Meet Leader",
reqs = [{type = 'active_quest_stage', value = 'princess_search', stage = 'stage5'}],
target = 'capture_wrapup_start',
target_option = 0,
},