Languages table on your PC needs to be updated
Cause : On some slow machines, or congested networks, Q++ will make a local copy of the Languages table to speed up Script verification. If someone has changed the Languages table since Q++ made a local copy, this message will alert you.
Consequences : Q++ will not be able to verify languages related properties of a Script until this message is addressed.
The option of using a local Languages table was built-in at the beginning of Q++, in case speed would be a concern (as it was for generated holidays). But this never became an issue, and for the moment Q++ does not use a local Languages table.
In summary; you should never get this message.