AttributeError: 'NoneType' object has no attribute 'symbolLayer'

AttributeError: 'NoneType' object has no attribute 'symbolLayer' 
Traceback (most recent call last):
  File "C:/Users/jpilbeam/AppData/Roaming/QGIS/QGIS3profilesdefault/python/pluginsqgis2webmaindialog.py", line 350, in saveMap
    feedback=self.feedback)
  File "C:/Users/jpilbeam/AppData/Roaming/QGIS/QGIS3profilesdefault/python/pluginsqgis2webleafletWriter.py", line 101, in write
    folder=dest_folder)
  File "C:/Users/jpilbeam/AppData/Roaming/QGIS/QGIS3profilesdefault/python/pluginsqgis2webleafletWriter.py", line 191, in writeLeaflet
    exp_crs, minify)
  File "C:/Users/jpilbeam/AppData/Roaming/QGIS/QGIS3profilesdefault/python/pluginsqgis2webutils.py", line 246, in exportVector
    if is25d(layer, canvas, restrictToExtent, extent):
  File "C:/Users/jpilbeam/AppData/Roaming/QGIS/QGIS3profilesdefault/python/pluginsqgis2webutils.py", line 513, in is25d
    sl1 = sym.symbolLayer(1)
AttributeError: 'NoneType' object has no attribute 'symbolLayer'


Python version: 3.7.0 (v3.7.0:1bf9cc5093, Jun 27 2018, 04:59:51) [MSC v.1914 64 bit (AMD64)] 
QGIS version: 3.12.1-București București, 121cc00ff0 
qgis2web version: 3.16.0

I’m using the qgis2web plugin and when I include the OpenStreetMap multipolygons layer I get this python error, which stops me from previewing and exporting to webmap. I can view and export with no problems when I don’t include that layer. So, I’m wondering if anyone has a clue as to where I should look to remedy this?

There has been an issue opened regarding this error on the qgis2web Github, but nothing recent.