Easiest way to manage local files?

I have spent the last 2 days trying to get somewhat of a usable setup going for my local music library.
All I want to do is use a program (preferably ncmpcpp) to access, queue, and play my library, while maintaining the ability to add to/edit my library as I wish.

My entire library is organized and tagged correctly, so there isn’t much work to do on that front.

I have tried and failed with pretty much every extension here to set up local file access. I can always get it kinda working, but not fully.

I tried using beets to create a fresh directory of my music (imported by beets) and pointed mopidy-beets-local towards my db file. This “works” and I can see my beets library in the file browser. However, everything lags and eventually mopidy and ncmpcpp stops working. Here is mopidy’s output during that:
WARNING get_distinct called field: artist, Query: {}
WARNING A client or frontend made a library search with an empty query. This is strongly discouraged. Please check what sent this query and file a bug.

I tried using local-sqlite3 and pointed mopidy towards that db file. I finally convinced mopidy local scan to run without errors. Any attempt to update the database within ncmpcpp freezes the program with the message
ncmpcpp cannot send a new message while recieving another response

I am running a FRESH install of Ubuntu 18.04. Is there something I’m not getting here? Getting mopidy/mpd/ncmpcpp to play nice together is an absolute nightmare. Can someone point me in the right direction to a guaranteed solution?

Does your Mopidy setup works correctly with the default Mopidy-local/json extension (https://docs.mopidy.com/en/latest/ext/local/)? And in combination with ncmpcpp?

If that works fine, what extra functionality do you expect from the Deezer or SQLLite extensions?

I just retried setting up Mopidy-local/json. Only the essentials enabled in the configs. Like before, I was able to configure mopidy to host a local mpd server and scan my library. Unfortunately, any tracks in the m4a format were not successfully imported. Additionaly, many perfectly good mp3s were ignored during the import as well. I pointed ncmpcpp to the local mpd server, and I am able to see and play all of the music that did get imported.

Are you abke to play m4a files using gstreamer (which is also used by Mopidy in the background)? If not your system be mussing the appropriate plugin. See https://github.com/mopidy/mopidy/issues/455.

Concerning the mp3 files, can you provide the output of the scan command and part of the mopidy log file that refers to this?