Error in htmlTreeParse

Hello! 
I've generated a customvisual based on a r script, however, I'm obtainning the follow error:

My Rscript is:

setwd("D:/IDGeo/Earth analytics course_Learn data science/data/week 4")
library(tidyverse)
library(htmlwidgets)
library(raster)
library(sf)
library(leaflet)
library(pandocfilters)
pivos <- st_read("california/SJER/vector_data/aneis_anapaula_0904.shp") %>%
st_transform(4326)
ndwi<- raster("california/SJER/vector_data/2017_06_04_NDWI_CLIP_wgs.tif")

chrt <- leaflet() %>%
 addProviderTiles(providers$CartoDB.Positron) %>% 
addPolygons(data = pivos, 
fillOpacity = 0,
stroke = T) %>%
addRasterImage(ndwi)
saveWidget(chrt, "chart.html")
chrt