'Basemap not available' when loading map in ArcGIS Online

[GavinMayeda]

I have created a map in ArcGIS Online and I have shared this map with my organization.  The person that this map is intended for has tried several times to open the map and is receiving the message "Basemap is not available.  Displaying the default basemap instead."

She is receiving this message when trying to open the map in Google Chrome (not IE 11).  I am able to open the map without issues in IE 11 and Chrome, but I receive this same message in Firefox.

Does anyone have any idea what is causing this, or have a workaround?  My office frowns on installing multiple browsers (Firefox is highly frowned upon).

As always, thank you all in advance for any insight!

Dell OptiPlex 9010

Intel(R) Core(TM) i7-3770 CPU @ 3.40 GHz

8.0 GB RAM

Windows 7 Professional 64-bit OS

AMD Radeon HD 7570

Dual Dell U2414H Monitors

[BrendanBladdick3]

What do the developer tools in Console and Network say?

Any red errors?

Open dev tools then try to add the layer again and see what errors pop up in Console and Network

[JoshSaad2]

I was having this issue this morning, but it started working again when I disabled my Privacy Badger extension.

[AndresCastillo]

I've also noticed in the past:

From one source aws server ip:

https://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer
is accessible using manual proxy server only.

yet,
https://internaldomain.example.com:port/webUrl
only available using the .pac setup script

In order for the .example.com addresses to work, I had to add *.example.com to the list of exceptions for the manual proxy server.

This is weird because in another equivalent server ( which has the same proxy/lan configurations----except the *.example.com exception) can reach both sites using the .pac setup script.
Other aws servers even only require the .pac setup script only!

I reference something similar here:
https://community.esri.com/t5/arcgis-pro-questions/create-new-python-environment/m-p/1002847/highlig...

[ChelseaRozek]

Happened to me in Chrome today. Clearing my cache once fixed it for me.