Paid products are missing
The VSTs (or plugins or soundfonts, whatever they are) that I bought from Musescore to use in Musescore 4 a while back to have a much more realistic piano sound (such as Grand Piano), string instruments, etc., are now gone (they were there a few days ago). They were a lot of fun to use to make the instruments sound more real. Where did they go? Now, it just says "MS Basic" in the mixer.
Comments
By "bought", what do you mean? The realistic sampled sounds should be free to download and use from the Muse Hub.
If you check the Muse Hub, are the sounds still downloaded?
MuseScore sell s no sounds at all. There are free downloads called Muse Sounds, and there are also paid products such as VST libraries from other companies. I can't help you with third party products you've purchased, but if you mean the free Muse Sounds, try re-downloading them via the Muse Hub.