Both .mp7 and .mp9 files are projects from NI Multisim circuit design software, albeit from different versions of the tool. This export is doable, but only in version 9 of NI Multisim, since the software is not backwards compatible and modern versions are not capable of saving to previously using formats. So if you need version 9 of the project, you have to use version 9 of the software, there is no way around this.
Updated: August 30, 2023