We have a silverlight application that consumes a map service from an enterprise ArcGIS Server. But it suddenly becomes very slow in earlier this year. Then we developed a testing application that uses ArcGIS API for JavaScript, by using MapImageLayer. But it returns mapimagelayer:image-fetch-error, unable to load image. However, when zooming in to a local area, the map does show up but takes long time.
In trouble shooting this, we developed another desktop application by using ArcGIS Runtime for .NET (ArcGISMapImageLayer) to test the issue is not within the server. The map can quickly shows up, without any issue. The speed is exactly like the silverlight application before the performance drops.
When testing ArcGIS API for Javascript, we did run on IE, Chrome, Firefox and Edge. The issue is persistent.
What are the possible reasons that running MapImageLayer of ArcGIS API for JavaScript in browser fails or slow but ArcGISMapImageLayer of ArcGIS Runtime for .NET maintains the fast performance?
Thanks!
