404 Not FoundMy GET and POST requests all work, but PUT and DELETE return status 404 from IIS and my code is never reached. I found it was necessary to go to IIS Manager > Web Site (or app) > Handler Mappings > double-click SimpleHandlerFactory-Integrated-4.0. In the dialog click Request Restrictions > Verbs tab > add PUT and DELETE and any other verbs you desire to the comma joined list.
401.3 Access is deniedI've overcome the 404 but now I get a security violation. Mercifully the default body of the response tells me it's a 401.3 which is an ACL violation on the ashx file. Procmon unexpectedly does not show me any Access Denied events to help me diagnose the violation. After a few experiments I conclude that you have to give Authenticated Users Read and Write permission to the ashx file.
And there goes another hour of my life I'll never get back.