Have recently updated to 28.0.3.51 and am no longer able to use any 3rd party Loops, the loops that work have to be "magix store" or "producer planet" just thought I would share, disappointing really );
I have the same problem.(2021 Version ) I can load them from the File manager but its a real ball ache. I prefer to use my extensive Cymatics collection as every sample is 100% royalty free and avoids any copyright issues https://cymatics.fm/ if you havent used them i recommend you check them out, Tonnes of free stuff on there.
Not sure why Magix have done this but its counter productive and extremely annoying
Please note that Music Maker 2021 is 64-bit as opposed to previous versions being 32-bit. This may be a reason for not being able to use 3rd party (assuming still being 32 bit).
Assuming you are referring audio samples ie audio loops from Cymatics there is no other way of adding them to MMM - they do not appear as Soundpools.
If you have VST's, MMM 2021 has a bridge to allow use of 32 bit VST's, and as this is a complete new install as opposed to a straight patch, the old VST paths may have been cleared and they need adding again.
The cymatics samples DID show as soundpools in the previous version. A few samples did not work correctly but i think it had something to do with the way i organised the folders.
It should not have an issue with the samples if the Program is 32 or 64 bit.
Magix are charging for the 32 to 64 VST converter whitch seems more of a money grab to me, If they change the bitrate of the program to 64bit surely the converter should be included.