Originally Posted by ShinyShoe
Looks like it must be time related as I just cut n paste a long reply and it works. I guess it knows I've taken too long to type and thinks i need to re authenticate something.
Its a "stop waffling" filter!
Tapatalk authentication has a cookie-like function which when you login gives the app a "session ID". The "session ID" expires at the server after a period of time. Every time you do something in the App that sends a message to the server (e.g. requesting a new page of threads) the server updates the expiry time of your "session ID". If you spend too long composing a message the content is sent with a now expired "session ID" so you get the error message you saw.
I don't know how long the expiry is set at - but the default is 15 minutes. The error could be trapped at the app - but (i) as JK says its not ours and (ii) normal people don't need it!