Harmonize Error Message

[sbckr]

When executing MPC Programs, computation may fail for players with different reasons. However, user will only be prompted one of the received error messaged, not allowing him to gain more insights into the issue causing the error.

E.g.
When ephemeral programs are executed and a game starts, some parties will try to establish connections for interim-data exchange to other players as of communication managed implemented in MP-SPDZ. These players might wait for the connections to be established and fail after a given timeout. If the program was triggered with a potential input it is unauthorized to access, some players may (more or less) immediately fail with error unauthorized. Still, the client will only receive one of the error messages.

One should either implement error handling such that all error received are printed, or better make sure that players fail for the same reason.