So, this is the odd behaviour I just came across while trying to open an existing map using the Explorer app. I received the "Invalid Token" message when I was trying to open one existing map but not for a different map created during the same time period last year.
Here is what I've figured out, it doesn't like a copy of a view, or at first glance that seems to be a basic assessment of what might be part of the issue.
When the map contained a feature layer (hosted, view) there were no issues opening the map up in Collector for ArcGIS or Explorer.
BUT if I made a copy of that view in the map so that I could have multiple versions of the same feature layer to symbolize the data differently based on filters, the map does not load and I receive the "invalid token" message. I did not change any sharing permissions.
By removing the copy of the layer but keeping the original feature layer (hosted, view) I was able to get the map to load correctly.
That's the "fix" I've managed to find.
