ERROR
Attempts to sync hosted layers from ArcGIS Desktop to ArcGIS Online or hosting Web Map Services (WMS) and Web Map Tile Services (WMTS) layers fail and return the following error:
Error: Authentication token required. (status code 499)
The error occurs when the layers are added from a previous project, for example, the layer is opened through ArcGIS Online by selecting the Open in ArcGIS Desktop option and added to the map. It is recommended to add the layer from the same data source of the added layers, instead of adding the layer from a previous project, since there may be issues with the old project that may be carried over.
As for hosting WMS or WMTS layers, this is a known limitation. The Open Geospatial Consortium (OGC) WMS services are secured with token-based authentication, and must be shared with everyone to be properly used.
Use one of the following suggestions to fix the error.
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