[CrazySchmidt]

That error message is displayed when MM is launched but can't find the FBPath.txt file, which should be located in the MM program folder. It is the file that holds the path info to your copy of IL-2. Without that info MM cannot interact with IL-2 correctly.

From your screen shot, it seems as if you are attempting to run MM from a temp download folder, which is not a good idea. The installation process should be as follows.
1. Extract the contents of the zip file onto you desktop or another location on your PC.
2. Run the setup exe and choose an installation location for MM.
3. Launch MM. The first time it loads after installation, MM will ask you to point to your chosen IL-2 program folder and it is this info that is written into the FBPath.txt file which is located in the main MM program folder.
That should be all you need to get running.

Also, it is not necessary to uninstall any previous version of MM because each new version is a complete install and is always installed into a new version folder, however I personally would always uninstall any previous version just to keep everything nice and clean.

Let me know how you get on.

CS.