One thought, that you’ve possibly considered, but I’ll mention it anyway...
I have been using a saved download of 2.19.65-1.mingw.exe 25,348 KB.
Installing today resulted in failure, no response from the command promt.
So I went back to 2.18.2 this did work from command prompt and Frescobaldi.
It seems there may be something in the 2.19.65-1 file that I have saved. Windows doesn’t like but without any error code it is impossible to track it down.
I cannot load any 2.19 version from the lilypond.org
In the more recent versions of 2.19.XX, something has caused a much more substantial wait time which is required for LilyPond to create its font cache for that particular LP version, and is required for any version when it is run for the first time or when there is a change to what fonts are installed in the system font folder.
What I’m getting at is that you may be not seeing anything in the command prompt because nothing is printed while this font cache is being created. If you aren’t seeing an error when you try to run LP, give it some time, perhaps even 10 minutes just to be sure. It just might be this that’s causing you grief. Once the font cache is created, you’ll see the much quicker score compile times you’re used to.
If you’ve gone through this exercise already and/or you’re experiencing something else then please ignore this. It’s good to know that what I’ve described is expected behavior anyway.