I'm running into this issue way too frequently now.
When I click on Run, simulator starts with the big blue triangle, nothing is shown in the console and the simulator window goes into Not responding state. I have to kill it.
Then I have to choose another run configuration which just starts a sample app from Garmin, click on Run->blue triangle->not responding->kill.
Click on run again->sample app starts without issue.
Change the run configuration back to my watchface, click on run, watchface starts without issue.
Then if the companion app sends a message back to the simulator, simulator goes into the Not responding state immediately.
This did not happen that regularly before and I don't know what causes it. Either the upgrade to SDK 2.4.1, using the new Store.getValue/setValue, or making a bunch of new settings which pushed the memory usage up to 75.1/92.1kB.
Any ideas?