Do not underestimate the misery a beta can cause you. I have learnt - and hopefully, after being burnt and then trying again several times, this is the last time.
Yesterday, having put up with Catalina nonsense for the past few weeks, I fiddled about with my Onenote notebooks. I rearranged them and they all seemed to sync up. Then my new iMac would not restart. Eventually my only option was to wipe it and start again (Backblaze, Time Machine and CCC did not work and I had been hoping for the best). I got things going with Mojave and started from scratch. Everything went ok apart from Onenot - which I rely on for my notes.
I now get 'Content Not Yet Available' for about 20% of my notes. I'd thought that Onenote, being 'in the cloud' would have some kind of backup -but my best guess is that, having rearranged my notes, and then my iMac going caput very shortly after, has meant that all these notes have been lost into the ether. They are not available on the cloud or on any of my other devices. So clearly, the advice is - do not ever use a beta if you ever care whatsoever about your data.
I had put up with the following with Catalalina - Mail : I had to login via Safari as it could not search, Books - nothing would open, Logic Pro X - the UI was so delayed and glitchy that it was unuseable - plus any plugins would make it not open, Logic Remote would not open, Akai Mpc would not launch, etc. A lot of these issues involved Apple's own software.
I put up with it because of the promise of Sidecar on my iPad pro - since I'm unwilling to buy a butterfly keyboard laptop, and my 2015 mbpro is dead. It all seemed to be worth it until the iMac died today, and even less worth it since about 1000 notes I'd imagined to be safe in the cloud, have now disappeared. I'm not blaming Apple for the latter, since it seems to be a miscommunication somewhere along the line between Apple and Microsoft, however, the general gist from my point of view is - don't mess with a beta - and depend on the cloud for backup at the same time.
I had stupidly believed that if something was in a cloud service, it was safe - but today's experience shows me that if you are on a beta, and are using a cloud service, it is vulnerable.
I feel like an idiot - and will not use an Apple beta again. I am also reconsidering my use of OneNote - as it seems like it can signal that its Notebooks are 'synced' when they are anything but.
A boring story for sure - but perhaps a warning for anyone who, like me, was thinking - 'What's the worse that can happen' when enticed by the new features of the latest beta.
The worst is - hundreds of hours of work down the drain - if you are stupid enough like me, to set aside best practices of Backblaze and Time Machine and CCC - in the interests of using the latest features of the latest Beta.
Postscript - I'd been waiting for Beta 6 on tenterhooks - because my new iMac was nearly unuseable - and thought I'd reorganize my OneNote setup as one of the few things that wouldn't be affected at a MacOS level. I guess I was unlucky in that Beta 5 crippled my computer at just the moment that OneNote was syncing? That's my best guess. Anyway - I think I'll give Catalina a miss and try the next one in 18 months at this rate
PostPostscript - The computer I'm using is a brand new 2019 27inch iMac, i9 - so not an issue of compatability I'd think.