I have tried the latest development snapshot and I have seen the following error on both Lethal Xcess (when running it on an STE and STF) and Obsession Pinball (in STE mode).
Exception Type: EXC_CRASH (SIGABRT)
Exception Codes: 0x0000000000000000, 0x0000000000000000
Application Specific Information:
Assertion failed: (CycleTime >= 0), function CycInt_ModifyInterrupt, file /Users/bobc/Downloads/hatari/src/cycInt.c, line 406.
However, the error does not occur on all games. I was able to play the STE enhanced PD game Attack Wave without a problem.