I'm trying to make some conditional effects plot using the cplot() funcion from "margins" package, but the confidence intervals doesn't show up. I can only see the regression line.

This is the code that I'm using:

dfexp3<-import(experimento3.pescafurtiva)

dfexp3<-select(dfexp3, 'run number'= '[run number]','step'= '[step]', 'cuota', 'multa' = 'multa-sobrepesca', 'control' = 'control-sobrepesca', 'sardinas totales' = 'count sardinas', 'pezqueñines' = 'count sardinas with [age < 1]', 'xoubiñas' = 'count sardinas with [age >= 1 and age < 2]', 'sardinas' = 'count sardinas with [age >= 2]', 'barcos totales' = 'count barcos', 'barcos legales' = 'count barcos with [color = red]', 'barcos furtivos' = 'count barcos with [color = yellow]', 'beneficios medios' = 'sum [beneficios] of barcos  / count barcos', 'beneficios medios de los barcos legales' = 'sum [beneficios] of barcos with [color = red] / count barcos with [color = red]', 'beneficios medios de los barcos furtivos' = 'sum [beneficios] of barcos with [color = yellow ] / count barcos with [color = yellow]')

dfexp3$`run number`<-dfexp3$`run number`+900
dfexp3$`beneficios medios de los barcos furtivos`[dfexp3$`beneficios medios de los barcos furtivos`=='<RuntimePrimitiveException>']<- '0'
dfexp3$`beneficios medios de los barcos legales`[dfexp3$`beneficios medios de los barcos legales`=='<RuntimePrimitiveException>']<- '0'
dfexp3$`beneficios medios`[dfexp3$`beneficios medios`=='<RuntimePrimitiveException>']<- '0'

dfexp3$`beneficios medios`<-as.numeric(dfexp3$`beneficios medios`)
dfexp3$`beneficios medios de los barcos legales` <-as.numeric(dfexp3$`beneficios medios de los barcos legales`)
dfexp3$`beneficios medios de los barcos furtivos` <-as.numeric(dfexp3$`beneficios medios de los barcos furtivos`)
dfexp3.a <- import(experimento3.a.pescafurtivalow)
dfexp3.a <- select(dfexp3.a,'run number'= '[run number]','step'= '[step]', 'cuota', 'multa' = 'multa-sobrepesca', 'control' = 'control-sobrepesca', 'sardinas totales' = 'count sardinas', 'pezqueñines' = 'count sardinas with [age < 1]', 'xoubiñas' = 'count sardinas with [age >= 1 and age < 2]', 'sardinas' = 'count sardinas with [age >= 2]', 'barcos totales' = 'count barcos', 'barcos legales' = 'count barcos with [color = red]', 'barcos furtivos' = 'count barcos with [color = yellow]', 'beneficios medios' = 'sum [beneficios] of barcos  / count barcos', 'beneficios medios de los barcos legales' = 'sum [beneficios] of barcos with [color = red] / count barcos with [color = red]', 'beneficios medios de los barcos furtivos' = 'sum [beneficios] of barcos with [color = yellow ] / count barcos with [color = yellow]')
dfexp3.a$`beneficios medios de los barcos furtivos`[dfexp3.a$`beneficios medios de los barcos furtivos`=='<RuntimePrimitiveException>'] <- '0'
dfexp3.a$`beneficios medios de los barcos legales`[dfexp3.a$`beneficios medios de los barcos legales`=='<RuntimePrimitiveException>'] <- '0'
dfexp3.a$`beneficios medios`[dfexp3.a$`beneficios medios`=='<RuntimePrimitiveException>'] <- '0'
dfexp3.a$`beneficios medios` <- as.numeric(dfexp3.a$`beneficios medios`)
dfexp3.a$`beneficios medios de los barcos legales`<-as.numeric(dfexp3.a$`beneficios medios de los barcos legales`)
dfexp3.a$`beneficios medios de los barcos furtivos` <-as.numeric(dfexp3.a$`beneficios medios de los barcos furtivos`)
dfexp3 <- dfexp3 %>% full_join(dfexp3.a)
dfexp3 <- dfexp3 %>% arrange(`run number`)


modeloexp3sardinas<-lm(``sardinas totales`` ~ multa + control + cuota, data =dfexp3)
cplot(modeloexp3sardinas,"multa")

Im following this instructions and I don't really know what am I doing wrong.

modeloexp3sardinas is a large lm and this is it's summary:

This is the plot I get: