Contexts are obsolete and should not be used. Contexts were introduced for Release 4.0 for high performance access to frequently required data. Since the introduction of ABAP Objects for Release 4.5, contexts have not been developed further. Since Release 6.40, contexts can be replaced by shared objects.
If a context cannot derive dependent data when you test it or execute the DEMAND statement, it can send a message to the user.
The way in which messages are handled in contexts depends on the type of module in which the context could not determine data. Table and function module modules handle messages differently. Other contexts used as modules can be broken down to table and function module level.