Some users were reporting a startup crash on switching to v1.2.5. [1][2]
I put it in a debugger, and found one cause. At memory region 0x19f81C, it stores the content of the PATH environemnt variable, and also adds to it using function sprintf(). When it reaches 0x1A0000, it crashes because of a buffer overflow - all because many development programs put themselves into the system path.
This is a buffer of around 2020 bytes.