Request failed: unacceptable content-type: text/html using AFNetworking 2.0

Setting my RequestOperationManager Response Serializer to HTTPResponseSerializer fixed the issue.

Objective-C

manager.responseSerializer = [AFHTTPResponseSerializer serializer];

Swift

manager.responseSerializer = AFHTTPResponseSerializer()

Making this change means I don't need to add acceptableContentTypes to every request I make.

I took @jaytrixz's answer/comment one step further and added "text/html" to the existing set of types. That way when they fix it on the server side to "application/json" or "text/json" I claim it'll work seamlessly.

  manager.responseSerializer.acceptableContentTypes = [manager.responseSerializer.acceptableContentTypes setByAddingObject:@"text/html"];

This means that your server is sending "text/html" instead of the already supported types. My solution was to add "text/html" to acceptableContentTypes set in AFURLResponseSerialization class. Just search for "acceptableContentTypes" and add @"text/html" to the set manually.

Of course, the ideal solution is to change the type sent from the server, but for that you will have to talk with the server team.