I did not manage to post an answer to the existing post(s) on this topic...so here's the new one.
There are quite a lot of bugs in the new MM2021. See Johne Baker's summary at https://www.magix.info/nl/forum/music-maker-2021-v29-x-x-x-bugs-list--1249510/ .
Having worked with MM2021 quite often (but only with music & soundpools) I reported to Magix support today what I see as the status right . Some highlights:
- the many error messages at startup have gone thanks to the recent patch
- stability is better, though still not overwhelming. MM2021 likes to be threatened like an old man: carefully, and not too fast. Compare it to the (still better) stability of the 64-bit Samplitude.
- refusal to load 'Vita-related' (mostly older) soundpool-instruments. It now seems more or less solved: sometimes they load...and sometimes they don't. Solution (mostly...) is a simple restart of MM2021.
- reloading some instruments in a reloaded project (this was the main issue of my question to Support) remains a problem....I still got to guide MM 'by hand', although often the program spontaneously points to the right directory...Does anyone have the same experience? (See screenshot below).