.MSJ File

File extension msj is mainly associated with the MicroSurvey CAD, a complete desktop survey and design program developed for surveyors, contractors and engineers.

It appears that .msj files contain various temporary data generated by the program during some processing or other operations.

How to open:

These files are generated for temporary purpose only, so it does not seem likely that you could access them manually.

How to convert:

A conversion of any kind for this type of .msj file is most likely not possible.