One of the functions of the imsimta cnbuild utility is to compile MTA configuration information into an image that can be quickly loaded. The compiled format is quite rigidly defined and often changes substantially between different versions of the MTA. Minor changes might occur as part of patch releases.
When such changes occur, an internal version field is also changed so that incompatible formats can be detected. The MTA components will halt with the above error when an incompatible format is detected. The solution to this problem is to generate a new, compiled configuration with the command imsimta cnbuild.
It is also a good idea to use the imsimta restart command to restart any resident MTA server processes, so they can obtain updated configuration information.