Based upon this question here, I am interested in any ideas on how this might come about. Note that I am not asking about how all examples of writing would/could be lost, but how usage of the written word would be lost.
The only cause that I could think of was a widespread disease causing something like profound dyslexia, but I am unsure whether that is either plausible, or would produce the effect that I am interested in - so I am interested in a confirmation that this may be viable, or an alternative to it.
The starting point is a world much like ours with written language well established.
The answer really needs to provide a context for this question to be applicable, although I do not consider the widespread destruction of writing itself to be a necessary component, merely its disuse. The linked question, in brief is: "What would be the consequences of the disappearance of writing?"
The fuller context of this question is that this change is a relatively sudden process taking place over no more than one or two generations. In terms of an answer, shorter timeframes are preferable (overnight would be really good). The key is that the written word is lost as a means of communication somehow, not that it is willingly surrendered or given up for something better.