Mbed project debug fails.
As it’s crashing in the startup code, put a breakpoint in that assembly (startup_stm32.s) on the first instruction after “Reset_Handler:” and try stepping through it.
I’d also look at the *.map file to see what was linked. Equivalent information is available by expanding the *.elf program in the Project Explorere view if the elf Binary Parser is installed and enabled.
The default_handler will catch a lot of interrupts so very hard to determine the cause.
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