Notes about the M_P file extension:
Incorrect file associations could be the result of underlying issues within your PC system. As such it is highly recommended to scan your PC for invalid registry entries, unused processes and other unfavourable system settings to identify slowdown issues.
The M_P file type is primarily associated with 'Pro/ENGINEER' by PTC. Pro/ENGINEER is a 3D product design product, featuring productivity tools that promote best practices in design while ensuring compliance with your industry and company standards. These files appear and disappear at various times when using Pro/ENGINEER. They are part of what PTC collectively calls "turd" files and the display of them in the program can be turned off in the options.