If you start MEmu (regardless via which method) then the executable adb.exe (Android Debug Bridge) as essential emulator component automatically gets started, too. I've noticed that if you close (all open instances) MEmu then adb.exe gets NOT automatically killed. Not a fatal error, because no CPU-usage is given, only RAM is unnecessarily used, but should get corrected, IMO.
MEmu by default is configured the way that Android installs apps automatically either to system (AKA internal SD-card) or to storage/emulated/0 (AKA external SD-card).
Internal SD-card by default is 512 MB of fixed size. External SD-card - where the shared folders MEmu Music, MEmu Photo, MEmu Video and MEmu Download are part of - by default is 32 GB of initial size and never should run out of space unless computer's storage space runs out of space. The latter of course only if one keeps photos, videos and music in the shared folders.
I believe this way MEmu basically tries to ensure that always enough storage space on Android's internal SD-card is available. But noone knows when the internal SD-card despite of this gets full. Probably it's already enough to install a dozen games? For example the 3 games Vainglory, Vector & IntoTheDead I've installed already occupy ~115 MB. And the player app Kodi eats ~35 MB.
Hence I suggest to configure MEmu's Android to always install apps to external SD-card by default. MEmu users actually aren't allowed to move apps to external SD-card, this obviously due to Android 4+ restrictions:
An error message such as
MEmu failed to start and about to close. In order to ensure the stability of the system, please don't delete the system application of the MEmu.
some guys unfortunately got isn't really useful at all, IMO. What does "the sytem application of the MEmu" mean? I don't know it.
Suggest to pay attention to https://www.facebook.com/memuplayer for timely updates.