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

Question

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.

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"];

On the server side, I added:

header('Content-type: application/json');

into my .php code and this also fixed the problem.

I solve this problem from a different perspective.

I think if the server sends JSON data with Content-Type: text/html header. It doesn't mean the server guy intended to send you some html but accidentally changed to JSON. It does mean the server guy just doesn't care about what the Content-Type header is. So if the server guy doesn't care as the client side you better ignore the Content-Type header as well. To ignore the Content-Type header check in AFNetworking

manager.responseSerializer.acceptableContentTypes = nil;

In this way the AFJSONResponseSerializer (the default one) will serialize the JSON data without checking Content-Type in response header.

A simple way to enable to receive "text/plain" content type:

manager.responseSerializer.acceptableContentTypes = [NSSet setWithObject:@"text/plain"];

Similarly if you wish to enable "text/html" content type:

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