Dorico 4 Crashing when saving

My Dorico 4.3.30 crashes when I save my project. Not every time, but perhaps every 4 times.
How can this be? It has only happened for a couple of weeks or so.
I use Mojave on a Mac. It has worked fint for a couple of years until two weeks ago. Nothing has really changed as far as I can tell. I have fairly limited space on my hard drive, but that also is nothing new.
Having freed up extra space last couple of days have not made a difference.
Any suggestions on solutions for this?
Thank you.

Please choose Help > Create Diagnostic Report and attach the resulting zip file here so we can take a look at the crash reports.

Thank you! Here it is.
Dorico (1.0 MB)

Thanks for the diagnostics. Unfortunately you’re experiencing a crash that’s related to the use of iCloud (even though I suspect you’re not actually saving anything to iCloud). Is upgrading beyond Mojave, e.g. to Catalina, a possibility for you? That should work more reliably.

Thank you. That is strange, and thank you for working it out. Perhaps somehow dealing with iCloud will solve it, will try.
I have put off upgrading because of Sib 7 projects that need transferring/XML-ing first. After my current job I aim to get on with it. Then I can also upgrade Dorico. Thanks for a great program, and for excellent quick responses!
I take the opportunity to sneak in a humble request for future updates if I may - a special super-button which doubles all note values, as well as time signature values, including tuplets… would be wonderful. Currently I work on an orchestral piece with a lot of changing time signatures, and I realise it would be a lot easier for the musicians to read were the quavers crotchets, the crotchets minims and so on…
Best wishes, Johan