Some information about it is to be found on our Trainer Troubleshooting Guide here, 3rd topic -> Link
In detail: This tmp file is created by the trainer in the Windows tmp folder/ C:\Users\YourWindowsUserNamet\AppData\Local\Temp\ which is hidden by default. You might need to enable -Hidden items- in the Explorer's -View- tab.
Temporarily create a folder exclusion for the Windows tmp folder in your AV/other security software, run the trainer with admin rights, create a file exclusion in your AV/others for ~Mnn133.tmp and delete the Windows tmp folder exclusion.
If you don't know how to exclude files and folders in your antivirus please visit our AV Notification page here, pick your product and read or watch how it's done. -> Link