No playback
Literally didn't change a thing, opened the new MuseScore and no playback, buttons greyed out.
When I initially installed the first version, that was it. No maintaining, no "extra" installations, no downloads, no configuration. Type some notes and press play.
It seems they shoved a bunch of new features in there and now have lost the initial reason people used it. I'll just go back to Logic and Sibelius if its going to be like this. May not be any simpler, but at least they don't change the way the program runs out of the box so I know exactly what to press.
Case in point: Searched for solution, found answer, said to select "View" then "Synthesizer". So I check MuseScore and they don't even have a synthesizer option there anymore. Searched help, no synthesizer anywhere. What a waste.
Comments
See https://musescore.org/en/node/96811
The4re are indeed lots of wonderful new features that users have requested over the years; we do listen to the many many requests that come in and continually strive to improve the product.
Unfortunately there are far more combinations of hardware, device drivers, operating systems, and settings than anyone can possibly keep track of, so even a program that worked fine 10 years ago doesn't always work so well any more on a newer computer. We, like everyone else, strive to keep up, but it ends up being impossible to test every single combination. Hopefully the suggestions in the article above help.
But, I'm not sure what version of MuseScore you are looking at, but Synthesizer is definitely there in the View menu, as far as I know this hasn't changed in over a decade.