Thanks for that - an uninstall/reinstall will not remove your content, however it is unlikely to stop the issue.
However could you try doing the following steps for me please. These will remove any custom assets/brushes you've added (along with any other customisations) so I would suggest you first export these to the relevant files (afassets, afbrushes etc) and then perform the following steps. This will create a backup of your user data folder as well, however it won't be in a format you can directly import so I would suggest still doing an export as mentioned above first. On
Go to Macintosh HD\Users\username\Library\Containers\
rename the 'com.seriflabs.affinitydesigner' folder to 'com.seriflabs.affinitydesigner.old' Note: If you're running Big Sur this name displays differently as 'Affinity Designer', so I would suggest copying this folder to your desktop and then deleting the original. Essentially just ensure you have a copy of the original folder somewhere different as we'll need this.
Now hold down Ctrl and run Affinity Designer
You should see a big list of checkboxes appear - if you don't you haven't held Ctrl down correctly
Click all of these and then press 'Clear'
This should clear any customization and should stop the crashing you're getting when making a preset. So you will need to re-import the files you exported at the start to get your content back
However could you also attach a zipped up copy of the folder you renamed/copied in Step 2 please? I would like to try and reproduce this crash locally with your user data. I've created a Dropbox link to our internal Dropbox account below to upload to: https://www.dropbox.com/request/tTRD04yFOQbD49l0g2Ya
