Spindump log is a macOS tool that collects information about the programs running on the Mac and can help record any issues that occur at the time of the spindump log is taken. It is often used to find out what an app is doing when it stops responding.

To collect the spindump log, reproduce the issue first and once Pixelmator Pro stops responding, follow the steps below:

1. Open the Activity Monitor app on your Mac
If the Activity Monitor app is not in the Dock, you can search for it using Spotlight Search. Just type in "Activity Monitor" into the search field.

2. Locate the diagnostics menu
Click the cog in the top left (or the More Options button at the top, if you're running macOS Big Sur).

3. Collect the log
In the More menu, choose Spindump and wait for the spindump log to be collected.

4. Share the spindump log with us
Copy and paste the generated info into a text file and send it to us at support@pixelmator.com