I've tried every Playdate SDK since the original release and the simulator still doesn't work for me. The window just opens with a frame and blank contents, and then closes a few seconds later. No error messages or anything.
Event Viewer just shows the following
Faulting application name: PlaydateSimulator.exe, version: 0.0.0.0, time stamp: 0x62351ba5
Faulting module name: PlaydateSimulator.exe, version: 0.0.0.0, time stamp: 0x62351ba5
Exception code: 0xc000041d
Fault offset: 0x000000000000d2a2
Faulting process ID: 0x8a4
Faulting application start time: 0x01d8486aee1a87a7
Faulting application path: C:\Users\[me]\Documents\PlaydateSDK\bin\PlaydateSimulator.exe
Faulting module path: C:\Users\[me]\Documents\PlaydateSDK\bin\PlaydateSimulator.exe
Report ID: a2c9e033-9f63-4901-9e3a-c62d978a016b
Faulting package full name:
Faulting package-relative application ID:
So that's exception code 0xc000041d
which is apparently "An unhandled exception was encountered during a user callback." according to what I can find on Google.
Seems like a bug in the simulator. Hopefully there's enough info here for you to fix it.