Our company has developed an application using Adobe FlashBuilder with Server Side communication via BlazeDS and Apache Tomcat 6.0. This application has been in production for years. In one part of our application, we have a Java method that can take 15 minutes to complete its task before returning results to the user. Since Firefox 29, about 5 minutes into the process, we now throw... [RPC Fault faultString="Channel disconnected" faultCode="Client.Error.DeliveryInDoubt" faultDetail="Channel disconnected before an acknowledgement was received"] at mx.rpc::AbstractInvoker/http://www.adobe.com/2006/flex/mx/internal::faultHandler()[E:\dev\4.y\frameworks\projects\rpc\src\mx\rpc\AbstractInvoker.as:345] at mx.rpc::Responder/fault()[E:\dev\4.y\frameworks\projects\rpc\src\mx\rpc\Responder.as:68] at mx.rpc::AsyncRequest/fault()[E:\dev\4.y\frameworks\projects\rpc\src\mx\rpc\AsyncRequest.as:113] at NetConnectionMessageResponder/channelDisconnectHandler()[E:\dev\4.y\frameworks\projects\rpc\src\mx\messaging\channels\NetConnectionChannel.as:689] at flash.events::EventDispatcher/dispatchEventFunction() at flash.events::EventDispatcher/dispatchEvent() at mx.messaging::Channel/disconnectSuccess()[E:\dev\4.y\frameworks\projects\rpc\src\mx\messaging\Channel.as:1203] at mx.messaging.channels::NetConnectionChannel/internalDisconnect()[E:\dev\4.y\frameworks\projects\rpc\src\mx\messaging\channels\NetConnectionChannel.as:175] at mx.messaging.channels::AMFChannel/internalDisconnect()[E:\dev\4.y\frameworks\projects\rpc\src\mx\messaging\channels\AMFChannel.as:355] at mx.messaging.channels::AMFChannel/statusHandler()[E:\dev\4.y\frameworks\projects\rpc\src\mx\messaging\channels\AMFChannel.as:445] The underlying code has not been changed in over a year. Performing the exact same operation in Google Chrome does not generate any errors.