3.7 web app that's been running for a few years now, just recently started having issues with the proxy.ashx. We have the latest .net proxy installed, ver 1.1.2, app/proxy both hosted on IIS 8.5. This is also the same machine running portal/server web adaptors.
When the app starts loading feature tables, the below request fails with: net::ERR_CONTENT_DECODING_FAILED 200 (OK)
https://app.ourdomain.com/proxy/proxy.ashx?https://gis.ourdomain.com/server/rest/services/Hosted/ReviewerDB2/FeatureServer/0/query?f=json&returnIdsOnly=true&token=1...
![response_headers.png response_headers.png](https://community.esri.com/t5/image/serverpage/image-id/19036i8BAFE99C382870D5/image-size/medium?v=v2&px=400)
If I try the request without going through the proxy, everything works as-expected. So ArcGIS server and the hosted datastore are all operating normally. The ArcGIS server logs also display nothing.
Other requests through the proxy and have no issues, like below.
https://app.ourdomain.com/proxy/proxy.ashx?https://gis.ourdomain.com/server/rest/services/Hosted/Rev...
![response_headers.png response_headers.png](https://community.esri.com/t5/image/serverpage/image-id/19037iC4C8AC190055A63B/image-size/medium?v=v2&px=400)
One last test was to comment out the proxy config from the JS web app
//esriConfig.defaults.io.proxyUrl = "/proxy/proxy.ashx"
//esriConfig.defaults.io.alwaysUseProxy = true;
Then "enable" CORS with JS API 3.7 via unsafe-eval.
<meta http-equiv="Content-Security-Policy" content="script-src 'self' 'unsafe-eval' https://js.arcgis.com; object-src 'self'">
Everything then works as-expected, but our customer will never be able to visit a site with unsafe-eval in the header.
Any advice here? What is all of a sudden going on with our .ashx proxy? .net Windows updates? IIS 8 updates?