ErrNoCurrSdk is caused when no sdk of the candidate is in use.

ErrArcNotIns is caused when the archive file does not exists in local directory.

ErrNoCand is caused if the candidate does not exists in registry.

ErrNoCurrCands is caused when no sdk is used now.

ErrNotOnline is caused by registry is not online.

ErrNoVer is caused if the version does not exists in registry.

ErrVerExists is caused when trying to install already installed version.

ErrVerInsFail is caused when installing version is failed.

ErrVerNotIns is caused when the version is not installed.