How to save Faceted Maps as html in tmap?

I created Faceted map using the following code:

STE_FACET <- tm_shape(SA4_AUST_2016) + tm_polygons("STE_NAME16", 
title = "STATES", id = "STE_NAME16", style="jenks", palette="BuPu") +
tm_facets(by="STE_NAME16", drop.NA.facets = TRUE, ncol = 3) +
tmap_options(limits = c(facets.view = 9))

Even though it created the map, it gave me the following warning message:

Warning message:
'mapview::latticeView' is deprecated.
Use 'leafsync::latticeView' instead.
See help("Deprecated") and help("mapview-deprecated").

I tried to save this map as HTML as follows:

tmap_save(STE_FACET, "STE_FACET.html")

However, I am getting the following error and warning messages:

Error in system.file(config, package = package) : 
'package' must be of length 1
In addition: Warning message:
'mapview::latticeView' is deprecated.
Use 'leafsync::latticeView' instead.
See help("Deprecated") and help("mapview-deprecated").

I am not clear with the error and warning messages and wondering how can I save the map as HTML.

Thanks

I'm having the same issue, no solution unfortunately. I wanted to add that (at least for me) if I change the same code to tm_facets(by = "mycolumn", as.layers = TRUE) to stack the layers instead of creating small multiples, I can export no problem. It seems like the issue is with the separate small multiples.