I have a WebApp application I am creating with the Web AppBuilder Developer Edition. In ArcMap, I created a custom print service like described here (https://enterprise.arcgis.com/en/server/latest/create-web-apps/windows/tutorial-publishing-additional-services-for-printing.htm). When I use the custom PrintService in the PrintWidget, no file is exported but an error is thrown: Error executing tool. Export Web Map.
When I copy the Web_Map_as_JSON code that is generated from the execute call, remove the basemap layer (https://services.arcgisonline.com/ArcGIS/rest/services/World_Topo_Map/MapServer) from the JSON code, I can get the PrintService to work when I execute from REST endpoint (execute) in the ArcGIS Server Manager.
But the combination of MapServices (hosted on an internal server) and the ESRI basemap does not work.
When I use the standard PrintService of WAB, I can get an export when I deselect all layers and only print the basemap, but when I add layers of my MapServices, it fails. However, since I need a custom template, I cannot use the standard PrintService.
Any idea what has to be done to make the print widget working with a custom PrintService and combine the ESRI basemap with MapServices hosted internally?