If you have a property in you page, let's say this one:
private String errorDescription;
and the error description is encoded like this:
then the ActivationRequestParameterWorker or to be more precise the URLEncoderImpl will throw an exception telling me there's an illegal character in my URL.
The '+' resolves to a space and spaces are not within the 'safe' BitSet within URLEncoderImpl. I encountered this while trying to read facebook error messages in my app (they are always passed as query parameters attached to a defined redirectURI).
I'm not able to change the way FB adds these parameters.
Would you mind changing the behaviour again to be less strict about the value of query parameters?