My FlexViewers are throwing this error this morning. Any ideas?
Is your site http or https?
We had issues with the USGS Map in Web AppBuilder because it is using an http link, and since our site is https, it wouldn't load.
Here is the link to the USGS National Map: USGSTopo (MapServer)
I hope this helps!
I think the service was just down. It started working again a little after I sent the message.
Thanks for your help,
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