>>/1218/
Thank you, I am glad you like it!
>>/1219/
>>/1220/
Thank you for this report. I am sorry for the trouble. I know that around that time (441), we moved to builds on Github. This was because my old macOS laptop (I think it was 10.13 High Sierra) was so old the things it made were incompatible with the new Big Sur. We now build on a Big Sur machine on the cloud. 439 isn't exactly when that happened, but I know I started work on newer version requirements for libraries around that time, so I am afraid I think this might just be a version incompatibility problem. Searching "LSOpenURLsWithRole 10810" shows a variety of similar versioning problems.
However there are also some things like this: https://www.mathworks.com/matlabcentral/answers/460920-why-do-i-get-the-error-lsopenurlswithrole-failed-with-error-10810-when-trying-to-install-matlab
Maybe this is related to security? Is your macOS set up with default security rules. I know you normally have to enable 'Allow apps downloaded from anywhere' as the Readme in the App dmg says.
I am not a macOS expert however. I thought that Mojave (10.14?) was compatible with Big-Sur-built Apps. I may be wrong, or it may just be more complicated than I understand. Do you happen to have a special version of python installed on your machine? Some of the searching I did on that error suggested a conflicting python install might cause it somehow.
I assume if you just run the App by double-clicking its icon (which would normally make a database in ~/Library I think), that doesn't work either?
If it seems like this is just a versioning problem--that Mojave (or your Mojave) is too old to run the Big Sur build, I think your best shot is to see about updating your machine to a later macOS. When we move to Qt 6 over this year, I am afraid I will have to say the same about Windows 7. Unfortunately, macOS seems to retire older OSes faster than Windows. Another potential answer here, if you have some python experience, although it sucks, is to run from source. It may be possible to keep using an older version of Qt, I imagine around 5.12 (check your help->about in v438 to see what Qt seems ok for you), if you are willing to go through the work of setting up a virtual environment and testing out different library versions. Here is my page on that, if you are interested: https://hydrusnetwork.github.io/hydrus/help/running_from_source.html
I think it would probably be easier to see about updating your OS though. And I am not convinced this is a versioning thing, I think it might be security related, maybe in combination with the new Big Sur executable.
Let me know how you get on.