So basicly you're saying that there may never be any new error, whatsoever?
If the application doesn't know an error, then it should treat it
as an "unknown error". After all, I _must_ be free to add new error
messages as they become necessary!
Of course you're free to add errors. But this error is different from a
normal error. This new error is a temporary error where the application
should just get the new timer list and try it again. This is imho
different from a normal error where the app most likely should give up.